Turbulent flows are known to produce enhanced effective magnetic and passive scalar diffusivities, which can fairly accurately be determined with numerical methods. It is now known that, if the flow is also helical, the effective magnetic diffusivity is reduced relative to the nonhelical value. Neither the usual second-order correlation approximation nor the various τ approaches have been able to capture this. Here we show that the helicity effect on the turbulent passive scalar diffusivity works in the opposite sense and leads to an enhancement. We have also demonstrated that the correlation time of the turbulent velocity field increases with the kinetic helicity. This is a key point in the theoretical interpretation of the obtained numerical results. Simulations in which helicity is being produced self-consistently by stratified rotating turbulence resulted in a turbulent passive scalar diffusivity that was found to be decreasing with increasing rotation rate.

The Draco Dwarf spheroidal (dSph) galaxy is one of the nearest and the most dark-matter-dominated satellites of the Milky Way. We obtained multiepoch near-infrared (NIR, JHK _s ) observations of the central region of Draco dSph covering a sky area of ∼21' × 21' using the WIRCam instrument at the 3.6 m Canada–France–Hawaii Telescope. Homogeneous JHK _s time-series photometry for 212 RR Lyrae (173 fundamental-mode, 24 first-overtone, and 15 mixed-mode variables) and five Anomalous Cepheids in Draco dSph are presented and used to derive their period–luminosity relations at NIR wavelengths for the first-time. The small scatter of ∼0.05 mag in these empirical relations for RR Lyrae stars is consistent with those in globular clusters and suggests a very small metallicity spread, up to ∼0.2 dex, among these centrally located variables. Based on empirically calibrated NIR period–luminosity–metallicity relations for RR Lyrae in globular clusters, we determined a distance modulus to Draco dSph of μ _RRL = 19.557 ± 0.026 mag. The calibrated K _s -band period–luminosity relations for Anomalous Cepheids in the Draco dSph and the Large Magellanic Cloud exhibit statistically consistent slopes but systematically different zero points, hinting at possible metallicity dependence of ∼ ‑ 0.3 mag dex^‑1. Finally, the apparent magnitudes of the tip of the red-giant branch in I and J bands also agree well with their absolute calibrations with the adopted RR Lyrae distance to Draco. Our recommended ∼1.5% precise RR Lyrae distance, D _Draco = 81.55 ± 0.98(statistical) ± 1.17(systematic) kpc, is the most accurate and precise distance to Draco dSph galaxy.

We present the results from a complex study of an eclipsing O-type binary (Aa+Ab) with the orbital period $P_{A}=3.2254367$ days, that forms part of a higher-order multiple system in a configuration (A+B)+C. We derived masses of the Aa+Ab binary $M_{1}= 19.02 \pm 0.12 \,M_\odot$, $M_{2}= 17.50 \pm 0.13 \,M_\odot$, radii $R_{1}= 7.70 \pm 0.05 \,R_\odot$, $R_{2}= 6.64 \pm 0.06 \,R_\odot$, and temperatures $T_1 = 34250 \pm 500 $ K, $T_2 = 33750 \pm 500 $ K. From the analysis of radial velocities, we found a spectroscopic orbit of A in the outer A+B system with $P_{A+B}=195.8$ days ($P_{A+B}/P_{A}\approx 61$). In the O-C analysis, we confirmed this orbit and found another component orbiting the A+B system with $P_{AB+C}=2550$ days ($P_{AB+C}\,/P_{A+B}\approx 13$). From the total mass of the inner binary and its outer orbit, we estimated the mass of the third object, $M_B \gtrsim 10.7 M_\odot$. From the light-travel time effect fit to the O-C data, we obtained the limit for the mass of the fourth component, $M_C \gtrsim 7.3 M_\odot$. These extra components contribute to about 20% to 30% (increasing with wavelength) of the total system light. From the comparison of model spectra with the multiband photometry, we derived a distance modulus of 18.59 $\pm$ 0.06 mag, a reddening of 0.16 $\pm$ 0.02 mag, and an $R_V$ of $3.2$. This work is part of our ongoing project, which aims to calibrate the surface brightness-color relation for early-type stars.

Metric perturbations induced by ultralight dark matter (ULDM) fields have long been identified as a potential target for pulsar timing array (PTA) observations. Previous works have focused on the coherent oscillation of metric perturbations at the characteristic frequency set by the ULDM mass. In this work, we show that ULDM fields source low-frequency stochastic metric fluctuations and that these low-frequency fluctuations can produce distinctive detectable signals in PTA data. Using the NANOGrav 12.5-yr dataset and synthetic datasets mimicking present and future PTA capabilities, we show that the current and future PTA observations provide the strongest probe of ULDM density within the Solar System for masses in the range of 10^-18 eV −10^-16 eV .

Context. Rotation is thought to influence the size of convective eddies and the efficiency of convective energy transport in the deep convection zones of stars. Rotationally constrained convection has been invoked to explain the lack of large-scale power in observations of solar flows.
Aims: Our main aims are to quantify the effects of rotation on the scale of convective eddies and velocity as well as the depths of convective overshoot and subadiabatic Deardorff layers.
Methods: We ran moderately turbulent three-dimensional hydrodynamic simulations of rotating convection in local Cartesian domains. The rotation rate and luminosity of the simulations were varied in order to probe the dependency of the results on Coriolis, Mach, and Richardson numbers measuring the influences of rotation, compressibility, and stiffness of the radiative layer. The results were compared with theoretical scaling results that assume a balance between Coriolis, inertial, and buoyancy (Archimedean) forces, also referred to as the CIA balance.
Results: The horizontal scale of convective eddies decreases as rotation increases, and it ultimately reaches a rotationally constrained regime consistent with the CIA balance. Using a new measure of the rotational influence on the system, we found that even the deep parts of the solar convection zone are not in the rotationally constrained regime. The simulations captured the slowly and rapidly rotating scaling laws predicted by theory, and the Sun appears to be in between these two regimes. Both the overshooting depth and the extent of the Deardorff layer decrease as rotation becomes more rapid. For sufficiently rapid rotation, the Deardorff layer is absent due to the symmetrisation of upflows and downflows. However, for the most rapidly rotating cases, the overshooting increases again due to unrealistically large Richardson numbers that allow convective columns to penetrate deep into the radiative layer.
Conclusions: Relating the simulations with the Sun suggests that the convective scale, even in the deep parts of the Sun, is only mildly affected by rotation and that some other mechanism is needed to explain the lack of strong large-scale flows in the Sun. Taking the current results at face value, the overshoot and Deardorff layers are estimated to span roughly 5% of the pressure scale height at the base of the convection zone in the Sun.

Axion-gluon interaction induces quadratic couplings between the axion and the matter fields. We find that, if the axion is an ultralight dark matter field, it induces small oscillations of the mass of the hadrons as well as other nuclear quantities. As a result, atomic energy levels oscillate. We use currently available atomic spectroscopy data to constrain such axion-gluon coupling. We also project the sensitivities of future experiments, such as ones using molecular and nuclear clock transitions. We show that current and near-future experiments constrain a finely tuned parameter space of axion models. These can compete with or dominate the already-existing constraints from oscillating neutron electric dipole moment and supernova bound, in addition to those expected from near future magnetometer-based experiments. We also briefly discuss the reach of accelerometers and interferometers.

We investigate the ten independent local form factors relevant to the b -baryon decay Λ_b→Λ ℓ+ℓ-,^{combininginformationof lattice QCD and dispersive bounds. We propose a novel parametrization of the form factors in terms of orthonormal polynomials that diagonalizes the form factor contributions to the dispersive bounds. This is a generalization of the unitarity bounds developed for meson-to-meson form factors. In contrast to ad hoc parametrizations of these form factors, our parametrization provides a degree of control of the form-factor uncertainties at large hadronic recoil. This is of phenomenological interest for theoretical predictions of, e.g., Λ_b→Λ γ and Λ_b→Λ ℓ+ℓ- decay processes.}

We present a simple parton-shower model that replaces the explicit angular ordering of the coherent branching formalism with a differentially accurate simulation of soft-gluon radiation by means of a non-trivial dependence of the splitting functions on azimuthal angles. We introduce a global kinematics mapping and provide an analytic proof that it satisfies the criteria for next-to leading logarithmic accuracy. In the new algorithm, initial and final state evolution are treated on the same footing. We provide an implementation for final-state evolution in the numerical code ALARIC and present a first comparison to experimental data.

We search for a B decay mode where one can find a peak for a D D ¯ bound state predicted in effective theories and in lattice QCD calculations, which has also been claimed from some reactions that show an accumulated strength in D D ¯ production at threshold. We find a good candidate in the B⁺→K⁺η η reaction, by looking at the η η mass distribution. The reaction proceeds via a first step in which one has the B⁺→D_s^*+D^{¯ 0} reaction followed by D_s^*+ decay to D⁰K⁺ and a posterior fusion of D⁰D^¯0 to η η , implemented through a triangle diagram that allows the D⁰D^¯0 to be virtual and to produce the bound state. The choice of η η to see the peak is based on results of calculations that find the η η among the light pseudoscalar channels with stronger coupling to the D D ¯ bound state. We find a neat peak around the predicted mass of that state in the η η mass distribution, with an integrated branching ratio for B⁺→K⁺ (D D ¯, bound); (D D ¯, bound) →η η of the order of 1.5 ×10^-4, a large number for hadronic B decays, which should motivate its experimental search.

Light (anti-) nuclei are a powerful tool both in collider physics and astrophysics. In searches for new and exotic physics, the expected small astrophysical backgrounds at low energies make these antinuclei ideal probes for, e.g., dark matter. At the same time, their composite structure and small binding energies imply that they can be used in collider experiments to probe the hadronization process and two-particle correlations. For the proper interpretation of such experimental studies, an improved theoretical understanding of (anti-) nuclei production in specific kinematic regions and detector setups is needed. In this work, we develop a coalescence framework for (anti-) deuteron production which accounts for both the emission volume and momentum correlations on an event-by-event basis: While momentum correlations can be provided by event generators, such as PYTHIA, the emission volume has to be derived from semiclassical considerations. Moreover, this framework goes beyond the equal-time approximation, which has been often assumed in femtoscopy experiments and (anti-) nucleus production models until now in small interacting systems. Using PYTHIA 8 as an event generator, we find that the equal-time approximation leads to an error of O (10 %) in low-energy processes like Υ decays, while the errors are negligible at CERN Large Hadron Collider energies. The framework introduced in this work paves the way for tuning event generators to (anti-) nuclei measurements.

Experimental searches for pure glueball states have proven challenging and so far yielded no results. This is believed to occur because glueballs mix with the ordinary q q bar states with the same quantum numbers. We will discuss an alternative mechanism, the formation of the glueball-meson molecular states. We will argue that the wave functions of already observed excited meson states may contain a significant part due to such molecular states. We discuss the phenomenology of glueball-meson molecules and comment on a possible charmless component of the XYZ states.

Context. The dead zone outer edge corresponds to the transition from the magnetically dead to the magnetorotational instability (MRI) active regions in the outer protoplanetary disk midplane. It has been previously hypothesized to be a prime location for dust particle trapping. A more consistent approach to access such an idea has yet to be developed, since the interplay between dust evolution and MRI-driven accretion over millions of years has been poorly understood.
Aims: We provide an important step toward a better understanding of the MRI-dust coevolution in protoplanetary disks. In this pilot study, we present a proof of concept that dust evolution ultimately plays a crucial role in the MRI activity.
Methods: First, we study how a fixed power-law dust size distribution with varying parameters impacts the MRI activity, especially the steady-state MRI-driven accretion, by employing and improving our previous 1+1D MRI-driven turbulence model. Second, we relax the steady-state accretion assumption in this disk accretion model, and partially couple it to a dust evolution model in order to investigate how the evolution of dust (dynamics and grain growth processes combined) and MRI-driven accretion are intertwined on million-year timescales, from a more sophisticated modeling of the gas ionization degree.
Results: Dust coagulation and settling lead to a higher gas ionization degree in the protoplanetary disk, resulting in stronger MRI-driven turbulence as well as a more compact dead zone. On the other hand, fragmentation has an opposite effect because it replenishes the disk in small dust particles which are very efficient at sweeping up free electrons and ions from the gas phase. Since the dust content of the disk decreases over millions of years of evolution due to radial drift, the MRI-driven turbulence overall becomes stronger and the dead zone more compact until the disk dust-gas mixture eventually behaves as a grain-free plasma. Furthermore, our results show that dust evolution alone does not lead to a complete reactivation of the dead zone. For typical T-Tauri stars, we find that the dead zone outer edge is expected to be located roughly between 10 au and 50 au during the disk lifetime for our choice of the magnetic field strength and configuration. Finally, the MRI activity evolution is expected to be crucially sensitive to the choice made for the minimum grain size of the dust distribution.
Conclusions: The MRI activity evolution (hence the temporal evolution of the MRI-induced α parameter) is controlled by dust evolution and occurs on a timescale of local dust growth, as long as there are enough dust particles in the disk to dominate the recombination process for the ionization chemistry. Once that is no longer the case, the MRI activity evolution is expected to be controlled by gas evolution and occurs on a viscous evolution timescale.

Light antinuclei, like antideuteron and antihelium-3, are ideal probes for new, exotic physics because their astrophysical backgrounds are suppressed at low energies. In order to exploit fully the inherent discovery potential of light antinuclei, a reliable description of their production cross sections in cosmic ray interactions is crucial. We provide therefore the cross sections of antideuteron and antihelium-3 production in pp, pHe, Hep, HeHe, p bar p and p bar He collisions at energies relevant for secondary production in the Milky Way, in a tabulated form which is convinient to use. These predictions are based on QGSJET-II-04m and the state of the art coalescence model WiFunC, which evaluates the coalesence probability on an event-by-event basis, including both momentum correlations and the dependence on the emission volume. In addition, we comment on the importance of a Monte Carlo description of the antideuteron production and on the use of event generators in general. In particular, we discuss the effect of two-particle momentum correlations provided by Monte Carlo event generators on antinuclei production.

A central requirement for the faithful implementation of large-scale lattice gauge theories (LGTs) on quantum simulators is the protection of the underlying gauge symmetry. Recent advancements in the experimental realizations of large-scale LGTs have been impressive, albeit mostly restricted to Abelian gauge groups. Guided by this requirement for gauge protection, we propose an experimentally feasible approach to implement large-scale non-Abelian $\mathrm{SU}(N)$ and $\mathrm{U}(N)$ LGTs with dynamical matter in $d+1$D, enabled by two-body spin-exchange interactions realizing local emergent gauge-symmetry stabilizer terms. We present two concrete proposals for $2+1$D $\mathrm{SU}(2)$ and $\mathrm{U}(2)$ LGTs, including dynamical matter and induced plaquette terms, that can be readily implemented in current ultracold-molecule and next-generation ultracold-atom platforms. We provide numerical benchmarks showcasing experimentally accessible dynamics, and demonstrate the stability of the underlying non-Abelian gauge invariance. We develop a method to obtain the effective gauge-invariant model featuring the relevant magnetic plaquette and minimal gauge-matter coupling terms. Our approach paves the way towards near-term realizations of large-scale non-Abelian quantum link models in analog quantum simulators.

Energetic jets that traverse the quark-gluon plasma created in heavy-ion collisions serve as excellent probes to study this new state of deconfined QCD matter. Presently, however, our ability to achieve a crisp theoretical interpretation of the crescent number of jet observables measured in experiments is hampered by the presence of selection biases. The aim of this work is to minimize those selection biases associated to the modification of the quark- versus gluon-initiated jet fraction in order to assess the presence of other medium-induced effects, namely, color decoherence, by exploring the rapidity dependence of jet substructure observables. So far, all jet substructure measurements at midrapidity have shown that heavy-ion jets are narrower than vacuum jets. We show both analytically and with Monte Carlo simulations that if the narrowing effect persists at forward rapidities, where the quark-initiated jet fraction is greatly increased, this could serve as an unambiguous experimental observation of color decoherence dynamics in heavy-ion collisions.

In this paper we focus on scattering amplitudes in maximally supersymmetric Yang-Mills theory and define a long sought-after geometry, the loop momentum amplituhedron, which we conjecture to encode tree and (the integrands of) loop amplitudes in spinor helicity variables. Motivated by the structure of amplitude singularities, we define an extended positive space, which enhances the Grassmannian space featuring at tree level, and a map which associates to each of its points tree-level kinematic variables and loop momenta. The image of this map is the loop momentum amplituhedron. Importantly, our formulation provides a global definition of the loop momenta. We conjecture that for all multiplicities and helicity sectors, there exists a canonical logarithmic differential form defined on this space, and provide its explicit form in a few examples.

Feedback mediated by cosmic rays (CRs) is an important process in galaxy formation. Because CRs are long-lived and because they are transported along the magnetic field lines independently of any gas flow, they can efficiently distribute their feedback energy within the galaxy. We present an in-depth investigation of (i) how CRs launch galactic winds from a disc that is forming in a $10^{11} \, \rm {M}_\odot$ halo and (ii) the state of CR transport inside the galactic wind. To this end, we use the AREPO moving-mesh code and model CR transport with the two-moment description of CR hydrodynamics. This model includes the CR interaction with the gyroresonant Alfvén waves that enable us to self-consistently calculate the CR diffusion coefficient and CR transport speeds based on coarse-grained models for plasma physical effects. This delivers insight into key questions such as whether the effective CR transport is streaming-like or diffusive-like, how the CR diffusion coefficient and transport speed change inside the circumgalactic medium, and to what degree the two-moment approximation is needed to faithfully capture these effects. We find that the CR-diffusion coefficient reaches a steady state in most environments with the notable exception of our newly discovered Alfvén-wave dark regions where the toroidal wind magnetic field is nearly perpendicular to the CR pressure gradient so that CRs are unable to excite the gyroresonant Alfvén waves. However, CR transport itself cannot reach a steady state and is not well described by either the CR streaming paradigm, the CR diffusion paradigm, or a combination of both.

We propose to replace the exact amplitudes used in Monte Carlo event generators for trained machine learning regressors, with the aim of speeding up the evaluation of slow amplitudes. As a proof of concept, we study the process g g →Z Z , whose leading-order amplitude is loop induced. We show that gradient boosting machines like XGBoost can predict the fully differential distributions with errors below 0.1%, and with prediction times O (10³) faster than the evaluation of the exact function. This is achieved with training times ∼ 23 minutes and regressors of size ≲ 22 Mb . We also find that XGBoost performs well over the entire phase space, while interpolation gives much larger errors in regions where the function is peaked. These results suggest a possible new avenue to speed up Monte Carlo event generators.

We generalize existing constraints on primordial black holes to dark objects with extended sizes using the aLIGO design sensitivity. We show that LIGO is sensitive to dark objects with radius O (10 −10³ km ) if they make up more than ∼O (10^-2−10^-3) of dark matter.

Recent experimental results in B physics from Belle, BABAR, and LHCb suggest new physics (NP) in the weak b →c charged-current processes. Here we focus specifically on the decay modes B^¯0→D^*+ℓ-ν^{¯ with ℓ=e and μ . The world averages of the ratios R_D and R_D* currently differ from the Standard Model (SM) predictions by 3.4 σ while recently a new anomaly has been observed in the forward-backward asymmetry measurement, A_FB , in B¯0→D*+μ-ν ¯ decay. It is found that Δ A_FB=A_FB(B →D*μ ν )-A_FB(B →D*e ν ) is around 4.1 σ away from the SM prediction in an analysis of 2019 Belle data. In this work we explore possible solutions to the Δ A_FB anomaly and point out correlated NP signals in other angular observables. These correlations between angular observables must be present in the case of beyond the Standard Model physics. We stress the importance of Δ type observables that are obtained by taking the difference of the observable for the muon and the electron mode. These quantities cancel form-factor uncertainties in the SM and allow for clean tests of NP. These intriguing results also suggest an urgent need for improved simulation and analysis techniques in B¯0→D*+ℓ-}ν^{¯ decays. Here we also describe a new Monte Carlo event generator tool based on EVTGEN that we developed to allow simulation of the NP signatures in B¯0→D*+ℓ-}ν^{, which arise due to the interference between the SM and NP amplitudes. We then discuss prospects for improved observables sensitive to NP couplings with 1, 5, 50, and 250 ab -1 of Belle II data, which seem to be ideally suited for this class of measurements.}

A subfraction of dark matter or new particles trapped inside celestial objects can significantly alter their macroscopic properties. We investigate the new physics imprint on celestial objects by using a generic framework to solve the Tolman-Oppenheimer-Volkoff (TOV) equations for up to two fluids. We test the impact of populations of new particles on celestial objects, including the sensitivity to self-interaction sizes, new particle mass, and net population mass. Applying our setup to neutron stars and boson stars, we find rich phenomenology for a range of these parameters, including the creation of extended atmospheres. These atmospheres are detectable by their impact on the tidal Love number, which can be measured at upcoming gravitational wave experiments such as Advanced LIGO, the Einstein Telescope, and LISA. We release our calculation framework as a publicly available code, allowing the TOV equations to be generically solved for arbitrary new physics models in novel and admixed celestial objects.

The recently developed B-Mesogenesis scenario predicts decays of B mesons into a baryon and hypothetical dark antibaryon Ψ. We suggest a method to calculate the amplitude of the simplest exclusive decay mode B⁺ → pΨ. Considering two models of B-Mesogenesis, we obtain the B → p hadronic matrix elements by applying QCD light-cone sum rules with the proton light-cone distribution amplitudes. We estimate the B⁺ → pΨ decay width as a function of the mass and effective coupling of the dark antibaryon.

We investigate the formation and evolution of 'primordial' dusty rings occurring in the inner regions of protoplanetary discs, with the help of long-term, coupled dust-gas, magnetohydrodynamic simulations. The simulations are global and start from the collapse phase of the parent cloud core, while the dead zone is calculated via an adaptive α formulation by taking into account the local ionization balance. The evolution of the dusty component includes its growth and back reaction on to the gas. Previously, using simulations with only a gas component, we showed that dynamical rings form at the inner edge of the dead zone. We find that when dust evolution, as well as magnetic field evolution in the flux-freezing limit are included, the dusty rings formed are more numerous and span a larger radial extent in the inner disc, while the dead zone is more robust and persists for a much longer time. We show that these dynamical rings concentrate enough dust mass to become streaming unstable, which should result in a rapid planetesimal formation even in the embedded phases of the system. The episodic outbursts caused by the magnetorotational instability have a significant impact on the evolution of the rings. The outbursts drain the inner disc of grown dust, however, the period between bursts is sufficiently long for the planetesimal growth via streaming instability. The dust mass contained within the rings is large enough to ultimately produce planetary systems with the core accretion scenario. The low-mass systems rarely undergo outbursts, and, thus, the conditions around such stars can be especially conducive for planet formation.

In this paper we present the complete expressions of the lepton and neutron electric dipole moments (EDMs) in the Standard Model Effective Field Theory (SMEFT), up to 1-loop and dimension-6 level and including both renormalization group running contributions and finite corrections. The latter play a fundamental role in the cases of operators that do not renormalize the dipoles, but there are also classes of operators for which they provide an important fraction, 10-20%, of the total 1-loop contribution, if the new physics scale is around Λ =5 TeV. We present the full set of bounds on each individual Wilson coefficient contributing to the EDMs using both the current experimental constraints, as well as those from future experiments, which are expected to improve by at least an order of magnitude.

We propose a parametrization of the leading B-meson light-cone distribution amplitude (LCDA) in heavy-quark effective theory (HQET). In position space, it uses a conformal transformation that yields a systematic Taylor expansion and an integral bound, which enables control of the truncation error. Our parametrization further produces compact analytical expressions for a variety of derived quantities. At a given reference scale, our momentum-space parametrization corresponds to an expansion in associated Laguerre polynomials, which turn into confluent hypergeometric functions ₁F₁ under renormalization-group evolution at one-loop accuracy. Our approach thus allows a straightforward and transparent implementation of a variety of phenomenological constraints, regardless of their origin. Moreover, we can include theoretical information on the Taylor coefficients by using the local operator product expansion. We showcase the versatility of the parametrization in a series of phenomenological pseudo-fits.

The dark matter halo sparsity, i.e. the ratio between spherical halo masses enclosing two different overdensities, provides a non-parametric proxy of the halo mass distribution that has been shown to be a sensitive probe of the cosmological imprint encoded in the mass profile of haloes hosting galaxy clusters. Mass estimations at several overdensities would allow for multiple sparsity measurements, which can potentially retrieve the entirety of the cosmological information imprinted on the halo profile. Here, we investigate the impact of multiple sparsity measurements on the cosmological model parameter inference. For this purpose, we analyse N-body halo catalogues from the Raygal and M2Csims simulations and evaluate the correlations among six different sparsities from spherical overdensity halo masses at Δ = 200, 500, 1000, and 2500 (in units of the critical density). Remarkably, sparsities associated to distinct halo mass shells are not highly correlated. This is not the case for sparsities obtained using halo masses estimated from the Navarro-Frenk-White (NFW) best-fitting profile, which artificially correlates different sparsities to order one. This implies that there is additional information in the mass profile beyond the NFW parametrization and that it can be exploited with multiple sparsities. In particular, from a likelihood analysis of synthetic average sparsity data, we show that cosmological parameter constraints significantly improve when increasing the number of sparsity combinations, though the constraints saturate beyond four sparsity estimates. We forecast constraints for the CHEX-MATE cluster sample and find that systematic mass bias errors mildly impact the parameter inference, though more studies are needed in this direction.

The impact of axion-like particles on the light polarization around the horizon of suppermassive black hole (SMBH) is discussed in the light of the latest polarization measurement of the Event Horizon Telescope (EHT). We investigate different sources of the polarization due to axion interaction with photons and the magnetic field of SMBH. These can modify the linear and circular polarization parameters of the emitted light. We have shown that a significant circular polarization can be produced via the photon scattering from the background magnetic field with axions as off-shell particles. This can further constrain the parameter space of ultralight axion-like particles and their couplings with photons. The future precise measurements of circular polarization can probe the features of ultralight axions in the near vicinity of SMBH.

We explore the effective field theory of a vector field X^μ that has a Stückelberg mass. The absence of a gauge symmetry for X^μ implies Lorentz-invariant operators are constructed directly from X^μ. Beyond the kinetic and mass terms, allowed interactions at the renormalizable level include X_μX^μH^†H , (X_μX^μ)², and X_μj^μ, where j^μ is a global current of the SM or of a hidden sector. We show that all of these interactions lead to scattering amplitudes that grow with powers of √{s }/m_X, except for the case of X_μj^μ where j^μ is a nonanomalous global current. The latter is well known when X is identified as a dark photon coupled to the electromagnetic current, often written equivalently as kinetic mixing between X and the photon. The power counting for the energy growth of the scattering amplitudes is facilitated by isolating the longitudinal enhancement. We examine in detail the interaction with an anomalous global vector current X_μj_anom^μ, carefully isolating the finite contribution to the fermion triangle diagram. We calculate the longitudinally-enhanced observables Z →X γ (when m_X<m_Z), f f ¯→X γ , and Z γ →Z γ when X couples to the baryon number current. Introducing a "fake" gauge-invariance by writing X^μ=A^μ-∂^μπ /m_X, the would-be gauge anomaly associated with A_μj_anom^μ is canceled by j_anom^μ∂_μπ /m_X; this is the four-dimensional Green-Schwarz anomaly-cancellation mechanism at work. Our analysis demonstrates there is a much larger set of possible interactions that an EFT with a Stückelberg vector field can have, revealing scattering amplitudes that grow with energy. The growth of these amplitudes can be tamed by a dark Higgs sector, but this requires dark Higgs boson interactions (and reintroduces fine-tuning in the dark Higgs sector) that can be separated from X interactions only in the limit g ≪1 .

A coupled-channel approach including the Λ_cD¯^(*) and ηcp channels in addition to the Σ_c^(*)D¯^(*) and J/ψp channels, as required by unitarity and heavy quark spin symmetry (HQSS), is applied to the hidden-charm pentaquark Pc states, i.e., P_c(4312), P_c(4440) and P_c(4457), discovered by LHCb Collaboration. It is demonstrated that to obtain cutoff independent results, the one-pion exchange potential in the multichannel systems is to be supplemented with next-leading order counter terms responsible for the S-wave-to-D-wave transitions. We show that the experimental data for the J/ψp mass distributions are fully in line with the Σ_cD¯ and Σ_cD¯^* hadronic molecular interpretation of the P_c(4312) and P_c(4440)/P_c(4457), respectively. A narrow Σ_c^*D¯ molecule around 4.38 GeV is required by the HQSS with the evidence for its existence seen in the J/ψp spectrum. Moreover, we predict the line shapes for the elastic and inelastic channels.

After playing a pivotal role in the birth of the Standard Model in the 70s, the study of charm physics has undergone a revival during the last decade, triggered by a wealth of precision measurements from the charm and B factories, and from the CDF and especially the LHCb experiments. In this paper, we sum up how the unique phenomenology of charmed hadrons can be used to test the Standard Model and we review the latest measurements performed in this field by the LHCb experiment. These include the historic first observations of CP violation and of a nonzero mass difference between the charmed neutral-meson mass eigenstates, the most precise determination of their decay-width difference to date, and a search for time-dependent CP violation reaching the unprecedented precision of 10−4. These results challenge our comprehension of nonperturbative strong interactions, and their interpretation calls for further studies on both the theoretical and experimental sides. The upcoming upgrades of the LHCb experiment will play a leading role in this quest.

Elliptic modular graph forms (eMGFs) are non-holomorphic modular forms depending on a modular parameter $\tau$ of a torus and marked points $z$ thereon. Traditionally, eMGFs are constructed from nested lattice sums over the discrete momenta on the worldsheet torus in closed-string genus-one amplitudes. In this work, we develop methods to translate the lattice-sum realization of eMGFs into iterated integrals over modular parameters $\tau$ of the torus with particular focus on cases with one marked point. Such iterated-integral representations manifest algebraic and differential relations among eMGFs and their degeneration limit $\tau \rightarrow i\infty$. From a mathematical point of view, our results yield concrete realizations of single-valued elliptic polylogarithms at arbitrary depth in terms of meromorphic iterated integrals over modular forms and their complex conjugates. The basis dimensions of eMGFs at fixed modular and transcendental weights are derived from a simple counting of iterated integrals and a generalization of Tsunogai's derivation algebra.

The most common predictions for rare K and B decay branching ratios in the Standard Model in the literature are based on the CKM elements | V_cb| and | V_ub| resulting from global fits, that are in the ballpark of their inclusive and exclusive determinations, respectively. In the present paper we follow another route, which to our knowledge has not been explored for Δ M_{s ,d} and rare K and B decays by anybody to date. We assume, in contrast to the prevailing inclusive expectations for | V_cb| , that the future true values of | V_cb| and | V_ub| will be both from exclusive determinations; in practice we use the most recent averages from FLAG. With the precisely known | V_us| the resulting rare decay branching ratios, ε_K, Δ M_d , Δ M_s and S_{ψ KS} depend then only on the angles β and γ in the unitarity triangle that moreover are correlated through the CKM unitarity. An unusual pattern of SM predictions results from this study with some existing tensions being dwarfed and new tensions being born. In particular using HPQCD B_s^{,d 0}-B_¯^{s ,d 0} hadronic matrix elements a 3.1 σ tension in Δ M_s independently of γ is found. For 60^∘≤γ ≤75^∘ the tension in Δ M_d between 4.0 σ and 1.1 σ is found and in the case of ε_K between 5.2 σ and 2.1 σ . Moreover, the room for new physics in K⁺→π⁺ν ν ¯ , K_L→π⁰ν ν ¯ and B →K (K^∗)ν ν ¯ decays is significantly increased. We compare the results in this EXCLUSIVE scenario with the HYBRID one in which | V_cb| in the former scenario is replaced by the most recent inclusive | V_cb| and present the dependence of all observables considered by us in both scenarios as functions of γ . As a byproduct we compare the determination of | V_cb| from Δ M_s , Δ M_d , ε_K and S_{ψ KS} using B_s^{,d 0}-B_¯^{s ,d 0} hadronic matrix elements from LQCD with 2 +1 +1 flavours, 2 +1 flavours and their average. Only for the 2 +1 +1 case values for β and γ exist for which the same value of | V_cb| is found: | V_cb|=42.6 (4 ) × 10^-3 , γ =64.6 (16^{) ∘} and β =22.2 (7^{) ∘} . This in turn implies a 2.7 σ anomaly in B_s→μ⁺μ^-.

We provide an extensive study of the lifetimes of singly charmed baryons and mesons, within the heavy quark expansion with all known corrections included. A special attention is devoted to the choice of the charm mass and wavefunctions of heavy baryons. We give our predictions for lifetimes, lifetime ratios, and semileptonic branching ratios of singly charmed baryons. Our results accommodate the experimentally-favoured hierarchy of singly charmed baryon lifetimes τ (Ξ_c⁰)<τ (Λ_c⁺)<τ (Ω_c⁰)<τ (Ξ_c⁺), in contrast to earlier theoretical findings. Predictions for charmed meson lifetimes and semileptonic decay rates are in agreement with a recent comprehensive study and experimental results within uncertainties.

In star-forming galaxies, the far-infrared (FIR) and radio-continuum luminosities obey a tight empirical relation over a large range of star-formation rates (SFR). To understand the physics, we examine magneto-hydrodynamic galaxy simulations, which follow the genesis of cosmic ray (CR) protons at supernovae and their advective and anisotropic diffusive transport. We show that gravitational collapse of the proto-galaxy generates a corrugated accretion shock, which injects turbulence and drives a small-scale magnetic dynamo. As the shock propagates outwards and the associated turbulence decays, the large velocity shear between the supersonically rotating cool disc with respect to the (partially) pressure-supported hot circumgalactic medium excites Kelvin-Helmholtz surface and body modes. Those interact non-linearly, inject additional turbulence and continuously drive multiple small-scale dynamos, which exponentially amplify weak seed magnetic fields. After saturation at small scales, they grow in scale to reach equipartition with thermal and CR energies in Milky Way-mass galaxies. In small galaxies, the magnetic energy saturates at the turbulent energy while it fails to reach equipartition with thermal and CR energies. We solve for steady-state spectra of CR protons, secondary electrons/positrons from hadronic CR-proton interactions with the interstellar medium, and primary shock-accelerated electrons at supernovae. The radio-synchrotron emission is dominated by primary electrons, irradiates the magnetised disc and bulge of our simulated Milky Way-mass galaxy and weakly traces bubble-shaped magnetically-loaded outflows. Our star-forming and star-bursting galaxies with saturated magnetic fields match the global FIR-radio correlation (FRC) across four orders of magnitude. Its intrinsic scatter arises due to (i) different magnetic saturation levels that result from different seed magnetic fields, (ii) different radio synchrotron luminosities for different specific SFRs at fixed SFR and (iii) a varying radio intensity with galactic inclination. In agreement with observations, several 100-pc-sized regions within star-forming galaxies also obey the FRC, while the centres of starbursts substantially exceed the FRC.

We study weak radiative |Δ c |=|Δ u |=1 decays of the charmed antitriplet (Λ_c, Ξ_c⁺, Ξ_c⁰) and sextet (Σ_c⁺⁺, Σ_c⁺, Σ_c⁰, Ξ_c^'+, Ξ_c^'0, Ω_c) baryons in the standard model (SM) and beyond. We work out S U (2 )- and S U (3 )_F-symmetry relations. We propose to study self-analyzing decay chains such as Ξ_c⁺→Σ⁺(→p π⁰)γ and Ξ_c⁰→Λ (→p π^-)γ , which enable new physics sensitive polarization studies. SM contributions can be controlled by a corresponding analysis of the Cabibbo-favored decays Λ_c⁺→Σ⁺(→p π⁰)γ and Ξ_c⁰→Ξ⁰(→Λ π⁰)γ . Further tests of the SM are available with initially polarized baryons including Λ_c→p γ together with Λ_c→Σ⁺γ decays, or Ω_c→Ξ⁰γ together with Ω_c→(Λ ,Σ⁰)γ . In addition, C P -violating new physics contributions to dipole operators can enhance C P asymmetries up to a few percent.

Finite density effects can destabilize the metastable vacua in relaxion models. Focusing on stars as nucleation seeds, we derive the conditions that lead to the formation and runaway of a relaxion bubble of a lower energy minimum than in vacuum. The resulting late-time phase transition in the universe allows us to set new constraints on the parameter space of relaxion models. We also find that similar instabilities can be triggered by the large electromagnetic fields around rotating neutron stars.

In this white paper for the Snowmass process, we review the status and prospects of the field of rare decays of b and c hadrons. The role that rare decays play in the search for physics beyond the Standard Model is emphasised. We stress the complementarity of a large set of relevant processes and outline the most promising directions. The experimental opportunities at Belle II, BES III, ATLAS, CMS, LHCb, and at future machines are discussed. We also summarize the challenges that need to be addressed on the theory side to achieve theory uncertainties for rare decays that match the expected experimental sensitivities.

Thermal electrons cannot directly participate in the process of diffusive acceleration at electron-ion shocks because their Larmor radii are smaller than the shock transition width: this is the well-known electron injection problem of diffusive shock acceleration. Instead, an efficient pre-acceleration process must exist that scatters electrons off of electromagnetic fluctuations on scales much shorter than the ion gyroradius. The recently found intermediate-scale instability provides a natural way to produce such fluctuations in parallel shocks. The instability drives comoving (with the upstream plasma) ion-cyclotron waves at the shock front and only operates when the drift speed is smaller than half of the electron Alfvén speed. Here we perform particle-in-cell simulations with the SHARP code to study the impact of this instability on electron acceleration at parallel nonrelativistic, electron-ion shocks. To this end, we compare a shock simulation in which the intermediate-scale instability is expected to grow to simulations where it is suppressed. In particular, the simulation with an Alfvénic Mach number large enough to quench the intermediate instability shows a great reduction (by two orders of magnitude) of the electron acceleration efficiency. Moreover, the simulation with a reduced ion-to-electron mass ratio (where the intermediate instability is also suppressed) not only artificially precludes electron acceleration but also results in erroneous electron and ion heating in the downstream and shock transition regions. This finding opens up a promising route for a plasma physical understanding of diffusive shock acceleration of electrons, which necessarily requires realistic mass ratios in simulations of collisionless electron-ion shocks.

We revisit the joint constraints in the mixed hot dark matter scenario in which both thermally produced QCD axions and relic neutrinos are present. Upon recomputing the cosmological axion abundance via recent advances in the literature, we improve the state-of-the-art analyses and provide updated bounds on axion and neutrino masses. By avoiding approximate methods, such as the instantaneous decoupling approximation, and limitations due to the limited validity of the perturbative approach in QCD that forced to artificially divide the constraints from the axion-pion and the axion-gluon production channels, we find robust and self-consistent limits. We investigate the two most popular axion frameworks: KSVZ and DFSZ. From Big Bang Nucleosynthesis (BBN) light element abundances data we find for the KSVZ axion $\Delta N_{\rm eff}<0.31$ and an axion mass bound $m_a < 0.53 $ eV (i.e., a bound on the axion decay constant $f_a > 1.07 \times 10^7$ GeV) both at $95\%$ CL. These BBN bounds are improved to $\Delta N_{\rm eff}<0.14$ and $m_a< 0.16$ eV ($f_a > 3.56 \times 10^7$ GeV) if a prior on the baryon energy density from Cosmic Microwave Background (CMB) data is assumed. When instead considering cosmological observations from the CMB temperature, polarization and lensing from the Planck satellite combined with large scale structure data we find $\Delta N_{\rm eff}<0.23$, $m_a< 0.28$ eV ($f_a > 2.02 \times 10^7$ GeV) and $\sum m_\nu < 0.16$ eV at $95\%$ CL. This corresponds approximately to a factor of $5$ improvement in the axion mass bound with respect to the existing limits. Very similar results are obtained for the DFSZ axion. We also forecast upcoming observations from future CMB and galaxy surveys, showing that they could reach percent level errors for $m_a\sim 1$ eV.

We perform the first calculation of form factors in the semileptonic decays B → D₁(2420)ℓν_ℓ and B → D₁^'(2430)ℓν_ℓ using QCD light-cone sum rules (LCSRs) with B-meson distribution amplitudes. In this calculation the c-quark mass is finite. Analytical expressions for two-particle contributions up to twist four are obtained. To disentangle the D₁ and D₁^' contributions in the LCSRs, we suggest a novel approach that introduces a combination of two interpolating currents for these charmed mesons. To fix all the parameters in the LCSRs, we use the two-point QCD sum rules for the decay constants of D₁ and D₁^' mesons augmented by a single experimental input, that is the B → D₁(2420)ℓν_ℓ decay width. We provide numerical results for all B → D₁ and B → D₁^' form factors. As a byproduct, we also obtain the D₁- and D₁^'-meson decay constants and predict the lepton-flavour universality ratios R(D₁) and R(D₁^').

We study gravothermal evolution of dark matter halos in the presence of differential self-scattering that has strong velocity and angular dependencies. We design controlled N-body simulations to model Rutherford and Moller scatterings in the halo, and follow its evolution in both core-expansion and -collapse phases. The simulations show the commonly-used transfer cross section underestimates the effects of dark matter self-interactions, but the viscosity cross section provides a good approximation for modeling angular-dependent dark matter scattering. We investigate thermodynamic properties of the halo, and find that the three moments of the Boltzmann equation under the fluid approximation are satisfied. We further propose a constant effective cross section, which integrates over the halo's characteristic velocity dispersion with weighting kernels motivated by kinetic theory of heat conduction. The effective cross section provides an approximation to differential self-scattering for most of the halo evolution. However, it can significantly underestimate the growth rate of the central density at late stages of the collapse phase. This indicates that constant and velocity-dependent dark matter self-interactions are fundamentally different, as for the latter the cross section evolves with the halo dynamically, boosting the collapse. This feature may help test different self-interacting dark matter models.

In this work we study possible connections between B-meson anomalies and Kaon physics observables in the context of combined solutions with the singlet and triplet scalar leptoquarks S₁ and S₃. By assuming a flavor structure for the leptoquark couplings dictated by a minimally broken U (2^{) 5} flavor symmetry we can make a sharp connection between these two classes of observables. We find that the bound on B (K⁺→π⁺ν ν ) from NA62 puts already some tension in the model, while the present limits on B (K_L→μ⁺μ^-) and μ →e conversion in nuclei can be saturated. Relaxing instead the flavor assumption we study what values for B (K⁺→π⁺ν ν ) , as well as for B (K_L→π⁰ν ν ) and B (K_{L ,S}→μ⁺μ^-) , are viable compatibly with all other phenomenological constraints.

A dark energy-like component in the early universe, known as early dark energy (EDE), is a proposed solution to the Hubble tension. Currently, there is no consensus in the literature as to whether EDE can simultaneously solve the Hubble tension and provide an adequate fit to the data from the cosmic microwave background (CMB) and large-scale structure of the universe. In this work, we deconstruct the current constraints from the Planck CMB and the full-shape clustering data of the Baryon Oscillation Spectroscopic Survey to understand the origin of different conclusions in the literature. We use two different analyses, a grid sampling and a profile likelihood, to investigate whether the current constraints suffer from volume effects upon marginalization and are biased toward some values of the EDE fraction, f _EDE. We find that the f _EDE allowed by the data strongly depends on the particular choice of the other parameters of the model, and that several choices of these parameters prefer larger values of f _EDE than in the Markov Chain Monte Carlo analysis. This suggests that volume effects are the reason behind the disagreement in the literature. Motivated by this, we use a profile likelihood to analyze the EDE model and compute a confidence interval for f _EDE, finding f _EDE = 0.072 ± 0.036 (68% C.L.). Our approach gives a confidence interval that is not subject to volume effects and provides a powerful tool to understand whether EDE is a possible solution to the Hubble tension.

In this note, as an input to the Snowmass studies, we provide a broad-brush picture of the physics output of future colliders as a function of their center of mass energies and luminosities. Instead of relying on precise projections of physics reaches, which are lacking in many cases, we mainly focused on simple benchmarks of physics yields, such as the number of Higgs boson produced. More detailed considerations for lepton colliders are given since there have been various recent proposals. A brief summary for hadron colliders based on a simple scaling estimate of the physics reaches is also included.

Flavor violating processes in the lepton sector have highly suppressed branching ratios in the standard model. Thus, observation of lepton flavor violation (LFV) constitutes a clear indication of physics beyond the standard model (BSM). We review new physics searches in the processes that violate the conservation of lepton (muon) flavor by two units with muonia and muonium–antimuonium oscillations.

We study the renormalization group of generic effective field theories that include gravity. We follow the on-shell amplitude approach, which provides a simple and efficient method to extract anomalous dimensions avoiding complications from gauge redundancies. As an invaluable tool we introduce a modified helicity h ∼ under which gravitons carry one unit instead of two. With this modified helicity we easily explain old and uncover new non-renormalization theorems for theories including gravitons. We provide complete results for the one-loop gravitational renormalization of a generic minimally coupled gauge theory with scalars and fermions and all orders in M_Pl, as well as for the renormalization of dimension-six operators including at least one graviton, all up to four external particles.

Solutions to vacuum Einstein field equations with cosmological constants, such as the de Sitter space and the anti-de Sitter space, are basic in different cosmological and theoretical developments. It is also well known that complex structures admit metrics of this type. The most famous example is the complex projective space endowed with the Fubini-Study metric. In this work, we perform a systematic study of Einstein complex geometries derived from a logarithmic Kähler potential. Depending on the different contribution to the argument of such logarithmic term, we shall distinguish among direct, inverted and hybrid coordinates. They are directly related to the signature of the metric and determine the maximum domain of the complex space where the geometry can be defined.

Recent experimental results in $B$ physics from Belle, BaBar and LHCb suggest new physics (NP) in the weak $b\to c$ charged-current and the $b\to s$ neutral-current processes. Here we focus on the charged-current case and specifically on the decay modes $B\to D^{*+}\ell^- \bar{\nu}$ with $\ell = e, \mu,$ and $\tau$. The world averages of the ratios $R_D$ and $R_D^{*}$ currently differ from the Standard Model (SM) by $3.4\sigma$ while $\Delta A_{FB} = A_{FB}(B\to D^{*} \mu\nu) - A_{FB} (B\to D^{*} e \nu)$ is found to be $4.1\sigma$ away from the SM prediction in an analysis of 2019 Belle data. These intriguing results suggest an urgent need for improved simulation and analysis techniques in $B\to D^{*+}\ell^- \bar{\nu}$ decays. Here we describe a Monte Carlo Event-generator tool based on EVTGEN developed to allow simulation of the NP signatures in $B\to D^*\ell^- \nu$, which arise due to the interference between the SM and NP amplitudes. As a demonstration of the proposed approach, we exhibit some examples of NP couplings that are consistent with current data and could explain the $\Delta A_{FB}$ anomaly in $B\to D^*\ell^- \nu$ while remaining consistent with other constraints. We show that the $\Delta$-type observables such as $\Delta A_{FB}$ and $\Delta S_5$ eliminate most QCD uncertainties from form factors and allow for clean measurements of NP. We introduce correlated observables that improve the sensitivity to NP. We discuss prospects for improved observables sensitive to NP couplings with the expected 50 ab$^{-1}$ of Belle II data, which seems to be ideally suited for this class of measurements.

The persistent tensions between inclusive and exclusive determinations of $|V_{cb}|$ and $|V_{ub}|$ weaken the power of theoretically clean rare $K$ and $B$ decays in the search for new physics (NP). We demonstrate how this uncertainty can be practically removed by considering within the SM suitable ratios of various branching ratios. This includes the branching ratios for $K^+\to\pi^+\nu\bar\nu$, $K_{L}\to\pi^0\nu\bar\nu$, $K_S\to\mu^+\mu^-$, $B_{s,d}\to\mu^+\mu^-$ and $B\to K(K^*)\nu\bar\nu$. Also $\epsilon_K$, $\Delta M_d$, $\Delta M_s$ and the mixing induced CP-asymmetry $S_{\psi K_S}$, all measured already very precisely, play an important role in this analysis. The highlights of our analysis are 16 $|V_{cb}|$ and $|V_{ub}|$ independent ratios that often are independent of the CKM arameters or depend only on the angles $\beta$ and $\gamma$ in the Unitarity Triangle with $\beta$ already precisely known and $\gamma$ to be measured precisely in the coming years by the LHCb and Belle II collaborations. Once $\gamma$ Once $\gamma$ is measured precisely these 16 ratios taken together are expected to be a powerful tool in the search for new physics. Assuming no NP in $|\epsilon_K|$ and $S_{\psi K_S}$ we determine independently of $|V_{cb}|$: $\mathcal{B}(K^+\to\pi^+\nu\bar\nu)_\text{SM}= (8.60\pm0.42)\times 10^{-11}$ and $\mathcal{B}(K_L\to\pi^0\nu\bar\nu)_\text{SM}=(2.94\pm 0.15)\times 10^{-11}$. This are the most precise determinations to date. Assuming no NP in $\Delta M_{s,d}$ allows to obtain analogous results for all $B$ decay branching ratios considered in our paper without any CKM uncertainties.

Context. X-ray- and extreme-ultraviolet- (XEUV-) driven photoevaporative winds acting on protoplanetary disks around young T Tauri stars may strongly impact disk evolution, affecting both gas and dust distributions. Small dust grains in the disk are entrained in the outflow and may produce a detectable signal. In this work, we investigate the possibility of detecting dusty outflows from transition disks with an inner cavity.
Aims: We compute dust densities for the wind regions of XEUV-irradiated transition disks and determine whether they can be observed at wavelengths 0.7 ≲ λ_obs [μm] ≲ 1.8 with current instrumentation.
Methods: We simulated dust trajectories on top of 2D hydrodynamical gas models of two transition disks with inner holes of 20 and 30 AU, irradiated by both X-ray and EUV spectra from a central T Tauri star. The trajectories and two different settling prescriptions for the dust distribution in the underlying disk were used to calculate wind density maps for individual grain sizes. Finally, the resulting dust densities were converted to synthetic observations in scattered and polarised light.
Results: For an XEUV-driven outflow around a M_* = 0.7 M_⊙ T Tauri star with L_X = 2 × 10³⁰ erg s^-1, we find dust mass-loss rates Ṁ_dust ≲ 2.0 × 10⁻³ Ṁ_gas, and if we invoke vertical settling, the outflow is quite collimated. The synthesised images exhibit a distinct chimney-like structure. The relative intensity of the chimneys is low, but their detection may still be feasible with current instrumentation under optimal conditions.
Conclusions: Our results motivate observational campaigns aimed at the detection of dusty photoevaporative winds in transition disks using JWST NIRCam and SPHERE IRDIS.

In this white paper for the Snowmass process, we discuss the prospects of probing new physics explanations of the persistent rare $B$ decay anomalies with a muon collider. If the anomalies are indirect signs of heavy new physics, non-standard rates for $\mu^+ \mu^- \to b s$ production should be observed with high significance at a muon collider with center of mass energy of $\sqrt{s} = 10$ TeV. The forward-backward asymmetry of the $b$-jet provides diagnostics of the chirality structure of the new physics couplings. In the absence of a signal, $\mu^+ \mu^- \to b s$ can indirectly probe new physics scales as large as $86$ TeV. Beam polarization would have an important impact on the new physics sensitivity.

To a good approximation, on large scales, the evolved two-point correlation function of biased tracers is related to the initial one by a convolution with a smearing kernel. For Gaussian initial conditions, the smearing kernel is Gaussian, so if the initial correlation function is parametrized using simple polynomials, then the evolved correlation function is a sum of generalized Laguerre functions of half-integer order. This motivates an analytic "Laguerre reconstruction" algorithm which previous work has shown is fast and accurate. This reconstruction requires as input the width of the smearing kernel. We show that the method can be extended to estimate the width of the smearing kernel from the same dataset. This estimate, and associated uncertainties, can then be used to marginalize over the distribution of reconstructed shapes and hence provide error estimates on the value of the distance scale. This procedure is not tied to a particular cosmological model. We also show that if, instead, we parametrize the evolved correlation function using simple polynomials, then the initial one is a sum of Hermite polynomials, again enabling fast and accurate deconvolution. If one is willing to use constraints on the smearing scale from other datasets, then marginalizing over its value is simpler for this latter, "Hermite" reconstruction, potentially providing further speed-ups in cosmological analyses.

Quantum coherence is one of the most striking features of quantum mechanics rooted in the superposition principle. Recently, it has been demonstrated that it is possible to harvest the quantum coherence from a coherent scalar field. In order to explore a new method of detecting axion dark matter, we consider a point-like Unruh-DeWitt detector coupled to the axion field and quantify a coherent measure of the detector. We show that the detector can harvest the quantum coherence from the axion dark matter. To be more precise, we consider a two-level electron system in an atom as the detector. In this case, we obtain the coherence measure C = 2.2 × 10−6γ(T/1s) where T and γ are an observation time and the Lorentz factor. At the same time, the axion mass ma we can probe is determined by the energy gap of the detector.

This is the second part of a thorough investigation of the redshift-space effects that affect void properties and the impact they have on cosmological tests. Here, we focus on the void-galaxy cross-correlation function, specifically, on the projected versions that we developed in a previous work. The pillar of the analysis is the one-to-one relationship between real and redshift-space voids above the shot-noise level identified with a spherical void finder. Under this mapping, void properties are affected by three effects: (i) a systematic expansion as a consequence of the distortions induced by galaxy dynamics, (ii) the Alcock-Paczynski volume effect, which manifests as an overall expansion or contraction depending on the fiducial cosmology, and (iii) a systematic off-centring along the line of sight as a consequence of the distortions induced by void dynamics. We found that correlations are also affected by an additional source of distortions: the ellipticity of voids. This is the first time that distortions due to the off-centring and ellipticity effects are detected and quantified. With a simplified test, we verified that the Gaussian streaming model is still robust provided all these effects are taken into account, laying the foundations for improvements in current models in order to obtain unbiased cosmological constraints from spectroscopic surveys. Besides this practical importance, this analysis also encodes key information about the structure and dynamics of the Universe at the largest scales. Furthermore, some of the effects constitute cosmological probes by themselves, as is the case of the void ellipticity.

Context. X-ray- and extreme-ultraviolet- (together: XEUV-) driven photoevaporative winds acting on protoplanetary disks around young T-Tauri stars may crucially impact disk evolution, affecting both gas and dust distributions.
Aims: We constrain the dust densities in a typical XEUV-driven outflow, and determine whether these winds can be observed at μm-wavelengths.
Methods: We used dust trajectories modelled atop a 2D hydrodynamical gas model of a protoplanetary disk irradiated by a central T-Tauri star. With these and two different prescriptions for the dust distribution in the underlying disk, we constructed wind density maps for individual grain sizes. We used the dust density distributions obtained to synthesise observations in scattered and polarised light.
Results: For an XEUV-driven outflow around a M_* = 0.7 M_⊙ T-Tauri star with L_X = 2 × 10³⁰ erg s⁻¹, we find a dust mass-loss rate Ṁ_dust ≲ 4.1 × 10⁻¹¹ M_⊙ yr⁻¹ for an optimistic estimate of dust densities in the wind (compared to Ṁ_gas ≈ 3.7 × 10⁻⁸ M_⊙ yr⁻¹). The synthesised scattered-light images suggest a distinct chimney structure emerging at intensities I∕I_max < 10^−4.5 (10^−3.5) at λ_obs = 1.6 (0.4) μm, while the features in the polarised-light images are even fainter. Observations synthesised from our model do not exhibit clear features for SPHERE IRDIS, but show a faint wind signature for JWST NIRCam under optimal conditions.
Conclusions: Unambiguous detections of photoevaporative XEUV winds launched from primordial disks are at least challenging with current instrumentation; this provides a possible explanation as to why disk winds are not routinely detected in scattered or polarised light. Our calculations show that disk scale heights retrieved from scattered-light observations should be only marginally affected by the presence of an XEUV wind.

We reemphasize the strong dependence of the branching ratios $B(K^+\to\pi^+\nu\bar\nu)$ and $B(K_L\to\pi^0\nu\bar\nu)$ on $|V_{cb}|$ that is stronger than in rare $B$ decays, in particular for $K_L\to\pi^0\nu\bar\nu$. Thereby the persistent tension between inclusive and exclusive determinations of $|V_{cb}|$ weakens the power of these theoretically clean decays in the search for new physics (NP). We demonstrate how this uncertainty can be practically removed by considering within the SM suitable ratios of the two branching ratios between each other and with other observables like the branching ratios for $K_S\to\mu^+\mu^-$, $B_{s,d}\to\mu^+\mu^-$ and $B\to K(K^*)\nu\bar\nu$. We use as basic CKM parameters $V_{us}$, $|V_{cb}|$ and the angles $\beta$ and $\gamma$ in the unitarity triangle (UT). This avoids the use of the problematic $|V_{ub}|$. A ratio involving $B(K^+\to\pi^+\nu\bar\nu)$ and $B(B_s\to\mu^+\mu^-)$ while being $|V_{cb}|$-independent exhibits sizable dependence on the angle $\gamma$. It should be of interest for several experimental groups in the coming years. We point out that the $|V_{cb}|$-independent ratio of $B(B^+\to K^+\nu\bar\nu)$ and $B(B_s\to\mu^+\mu^-)$ from Belle II and LHCb signals a $1.8\sigma$ tension with its SM value. As a complementary test of the Standard Model, we propose to extract $|V_{cb}|$ from different observables as a function of $\beta$ and $\gamma$. We illustrate this with $\epsilon_K$, $\Delta M_d$ and $\Delta M_s$ finding tensions between these three determinations of $|V_{cb}|$ within the SM. From $\Delta M_s$ and $S_{\psi K_S}$ alone we find $|V_{cb}|=41.8(6)\times 10^{-3}$ and $|V_{ub}|=3.65(12)\times 10^{-3}$. We stress the importance of a precise measurement of $\gamma$. We obtain most precise SM predictions for considered branching ratios of rare K and B decays to date.

Accreting supermassive binary black holes (SMBBHs) are potential multimessenger sources because they emit both gravitational-wave and electromagnetic (EM) radiation. Past work has shown that their EM output may be periodically modulated by an asymmetric density distribution in the circumbinary disk, often called an "overdensity" or "lump;" this modulation could possibly be used to identify a source as a binary. We explore the sensitivity of the overdensity to SMBBH mass ratio and magnetic flux through the accretion disk. We find that the relative amplitude of the overdensity and its associated EM periodic signal both degrade with diminishing mass ratio, vanishing altogether somewhere between 1:2 and 1:5. Greater magnetization also weakens the lump and any modulation of the light output. We develop a model to describe how lump formation results from internal stress degrading faster in the lump region than it can be rejuvenated through accretion inflow, and predicts a threshold value in specific internal stress below which lump formation should occur and which all our lump-forming simulations satisfy. Thus, detection of such a modulation would provide a constraint on both mass ratio and magnetic flux piercing the accretion flow.

One of the most fundamental questions in cosmology is if dark energy is related just to a constant or it is something more complex. In this work, we call the attention to the fact that, under very general conditions, dark energy can be identified with a cosmological constant. Indeed, this fact defines what we call Vacuum Frame. In general, this frame does not coincide with the Jordan or Einstein frame, defined by the invariant character of particle masses or the Newton constant, respectively. We illustrate this question by the introduction of a particular scalar-tensor model where the different hierarchies among these energy scales are dynamically generated.

We analyze in detail the angular distributions in B ¯ →D^∗ℓ ν ¯ decays, with a focus on lepton-flavour non-universality. We investigate the minimal number of angular observables that fully describes current and upcoming datasets, and explore their sensitivity to physics beyond the Standard Model (BSM) in the most general weak effective theory. We apply our findings to the current datasets, extract the non-redundant set of angular observables from the data, and compare to precise SM predictions that include lepton-flavour universality violating mass effects. Our analysis shows that the number of independent angular observables that can be inferred from current experimental data is limited to only four. These are insufficient to extract the full set of relevant BSM parameters. We uncover a ∼4 σ tension between data and predictions that is hidden in the redundant presentation of the Belle 2018 data on B ¯ →D^∗ℓ ν ¯ decays. This tension specifically involves observables that probe e -μ lepton-flavour universality. However, we find inconsistencies in these data, which renders results based on it suspicious. Nevertheless, we discuss which generic BSM scenarios could explain the tension, in the case that the inconsistencies do not affect the data materially. Our findings highlight that e -μ non-universality in the SM, introduced by the finite muon mass, is already significant in a subset of angular observables with respect to the experimental precision.

Our ordinary life changed quite a bit in March of 2020 due to the global Covid-19 pandemic. While spring time in general well awaited and regarded as a synonym for rejuvenation the spring of 2020 brought lock-down, curfew, home office and digital education to the lives of many. The particle physics community was not an exception: research institutes and universities introduced home office and digital lecturing and all workshops, conferences and summer schools were canceled, got postponed or took place online. Using publicly available data from the INSPIRE and arXiv databases we investigate the effects of this dramatic change of life to the publishing trends of the high-energy physics community with an emphasis on particle phenomenology and theory. To get insights we gather information about publishing trends in the last 20 years, and analyse it in detail.

Messier 15 (NGC 7078) is an old and metal-poor post core-collapse globular cluster that hosts a rich population of variable stars. We report new optical (gi) and near-infrared (NIR, JK_s) multi-epoch observations for 129 RR Lyrae, 4 Population II Cepheids (3 BL Herculis, 1 W Virginis), and 1 anomalous Cepheid variable candidate in M15 obtained using the MegaCam and the WIRCam instruments on the 3.6 m Canada-France-Hawaii Telescope. Multi-band data are used to improve the periods and classification of variable stars, and determine accurate mean magnitudes and pulsational amplitudes from the light curves fitted with optical and NIR templates. We derive optical and NIR period-luminosity relations for RR Lyrae stars which are best constrained in the K_s band, ${m}_{{K}_{s}}=-2.333\,(0.054)\mathrm{log}P+13.948\,(0.015)$ with a scatter of only 0.037 mag. Theoretical and empirical calibrations of RR Lyrae period-luminosity-metallicity relations are used to derive a true distance modulus to M15: 15.196 ± 0.026 (statistical) ± 0.039 (systematic) mag. Our precise distance moduli based on RR Lyrae stars and Population II Cepheid variables are mutually consistent and agree with recent distance measurements in the literature based on Gaia parallaxes and other independent methods.

We present results of the Relic Axion Dark-Matter Exploratory Setup (RADES), a detector which is part of the CERN Axion Solar Telescope (CAST), searching for axion dark matter in the 34.67 μeV mass range. A radio frequency cavity consisting of 5 sub-cavities coupled by inductive irises took physics data inside the CAST dipole magnet for the first time using this filter-like haloscope geometry. An exclusion limit with a 95% credibility level on the axion-photon coupling constant of g_aγ ≳ 4 × 10⁻¹³ GeV⁻¹ over a mass range of 34.6738 μeV < m_a< 34.6771 μeV is set. This constitutes a significant improvement over the current strongest limit set by CAST at this mass and is at the same time one of the most sensitive direct searches for an axion dark matter candidate above the mass of 25 μeV. The results also demonstrate the feasibility of exploring a wider mass range around the value probed by CAST-RADES in this work using similar coherent resonant cavities.

We measure the galaxy two- and three-point correlation functions at z = [0.5, 0.7] and z = [0.7, 0.9], from the Public Data Release 2 (PDR2) of the VIMOS Public Extragalactic Redshift Survey (VIPERS). We model the two statistics including a non-linear one-loop model for the two-point function and a tree-level model for the three-point function, and perform a joint likelihood analysis. The entire process and non-linear corrections are tested and validated through the use of the 153 highly realistic VIPERS mock catalogues, showing that they are robust down to scales as small as 10 $h^{-1} \, \mathrm{Mpc}$. The mocks are also adopted to compute the covariance matrix that we use for the joint two- and three-point analysis. Despite the limited statistics of the two (volume-limited) subsamples analysed, we demonstrate that such a combination successfully breaks the degeneracy existing at two-point level between clustering amplitude σ₈, linear bias b₁, and the linear growth rate of fluctuations f. For the latter, in particular, we measure $f(z=0.61)=0.64^{+0.55}_{-0.37}$ and f(z = 0.8) = 1.0 ± 1.0, while the amplitude of clustering is found to be σ₈(z = 0.61) = 0.50 ± 0.12 and $\sigma _8(z=0.8)=0.39^{+0.11}_{-0.13}$. These values are in excellent agreement with the extrapolation of a Planck cosmology.

Expressions for the potentials appearing in the nonrelativistic effective field theory description of doubly heavy baryons are known in terms of operator insertions in the Wilson loop. However, their evaluation requires nonperturbative techniques, such as lattice QCD, and the relevant calculations are often not available. We propose a parametrization of these potentials with a minimal model dependence based on an interpolation of the short- and long-distance descriptions. The short-distance description is obtained from weakly-coupled potential NRQCD and the long-distance one is computed using an effective string theory. The effective string theory coincides with the one for pure gluodynamics with the addition of a fermion field constrained to move on the string. We compute the hyperfine contributions to the doubly heavy baryon spectrum. The unknown parameters are obtained from heavy quark-diquark symmetry or fitted to the available lattice-QCD determinations of the hyperfine splittings. Using these parameters we compute the double charm and bottom baryon spectrum including the hyperfine contributions. We compare our results with those of other approaches and find that our results are closer to lattice-QCD determinations, in particular for the excited states. Furthermore, we compute the vacuum energy in the effective string theory and show that the fermion field contribution produces the running of the string tension and a change of sign in the Lüscher term.

Despite strong evidence for the existence of large amounts of dark matter (DM) in our Universe, there is no direct indication of its presence in our own solar system. All estimates of the local DM density rely on extrapolating results on much larger scales. We demonstrate for the first time the possibility of simultaneously measuring the local DM density and interaction cross section with a direct detection experiment. It relies on the assumption that incoming DM particles frequently scatter on terrestrial nuclei prior to detection, inducing an additional time-dependence of the signal. We show that for sub-GeV DM, with a large spin-independent DM-proton cross section, future direct detection experiments should be able to reconstruct the local DM density with smaller than 50% uncertainty.

I give a theory motivation for future measurements in quark flavour physics, trying to identify observables, which are less familiar, but nevertheless interesting and promising.

We present 3D calculations for dielectric haloscopes such as the currently envisioned MADMAX experiment. For ideal systems with perfectly flat, parallel and isotropic dielectric disks of finite diameter, we find that a geometrical form factor reduces the emitted power by up to 30 % compared to earlier 1D calculations. We derive the emitted beam shape, which is important for antenna design. We show that realistic dark matter axion velocities of 10^-3 c and inhomogeneities of the external magnetic field at the scale of 10 % have negligible impact on the sensitivity of MADMAX. We investigate design requirements for which the emitted power changes by less than 20 % for a benchmark boost factor with a bandwidth of 50 MHz at 22 GHz, corresponding to an axion mass of 90 μ eV. We find that the maximum allowed disk tilt is 100 μ m divided by the disk diameter, the required disk planarity is 20 μ m (min-to-max) or better, and the maximum allowed surface roughness is 100 μ m (min-to-max). We show how using tiled dielectric disks glued together from multiple smaller patches can affect the beam shape and antenna coupling.

Fitting half-integer generalized Laguerre functions to the evolved, real-space dark matter and halo correlation functions provides a simple way to reconstruct their initial shapes. We show that this methodology also works well in a wide variety of realistic, assembly biased, velocity biased and redshift-space distorted mock galaxy catalogs. We use the linear point feature in the monopole of the redshift-space distorted correlation function to quantify the accuracy of our approach. We find that the linear point estimated from the mock galaxy catalogs is insensitive to the details of the biasing scheme at the subpercent level. However, the linear point scale in the nonlinear, biased, and redshift-space distorted field is systematically offset from its scale in the unbiased linear density fluctuation field by more than 1%. In the Laguerre reconstructed correlation function, this is reduced to sub-percent values, so it provides comparable accuracy and precision to methods that reconstruct the full density field before estimating the distance scale. The linear point in the reconstructed density fields provided by these other methods is likewise precise, accurate, and insensitive to galaxy bias. All reconstructions depend on some input parameters, and marginalizing over uncertainties in the input parameters required for reconstruction can degrade both accuracy and precision. The linear point simplifies the marginalization process, enabling more realistic estimates of the precision of the distance scale estimate for negligible additional computational cost. We show this explicitly for Laguerre reconstruction.

We find the complete set of conditions satisfied by the forward 2 →2 scattering amplitude in unitary and causal theories. These are based on an infinite set of energy dependent quantities (the arcs) which are dispersively expressed as moments of a positive measure defined at (arbitrarily) higher energies. We identify optimal finite subsets of constraints, suitable to bound effective field theories (EFTs), at any finite order in the energy expansion. At tree level arcs are in a one to one correspondence with Wilson coefficients. We establish under which conditions this approximation applies, identifying seemingly viable EFTs where it never does. In all cases, we discuss the range of validity in both energy and couplings, where the latter has to satisfy two-sided bounds. We also extend our results to the case of small but finite t . A consequence of our study is that EFTs in which the scattering amplitude in some regime grows in energy faster than E⁶ cannot be UV completed.

We study the transition widths of ϒ (10753 ) and ϒ (11020 ) into standard bottomonium under the hypothesis that they correspond to the two lowest laying 1^-- hybrid bottomonium states. We employ weakly coupled potential NRQCD an effective field theory incorporating the heavy-quark and multipole expansions. We consider the transitions generated by the leading order and next-to-leading order singlet-octet operators. In the multipole expansion the heavy-quark matrix elements factorize from the production of light-quark mesons by gluonic operators. For the leading order operator we compute the widths with a single π⁰, η or η^' in the final state and for the next-to-leading operator for π⁺π^- or K⁺K^-. The hadronization of the gluonic operators is obtained, in the first case, from the axial anomaly and a standard π⁰-η -η^' mixing scheme and, in the second case, we employ a coupled-channel dispersive representation matched to chiral perturbation theory for both the S - and D -wave pieces of the gluonic operator. We compare with experimental values and semi-inclusive widths. Our results strongly suggest that ϒ (11020 ) is indeed a hybrid bottomonium state.

Hydroxyl ($\rm OH$) is known to form efficiently in cold gas (T ~ 100 K) along with the molecule $\rm H_2$ and can be used as an efficient tracer of the diffuse molecular gas in the interstellar medium (ISM). Using a simple formalism describing the $\rm H\, I/H_2$ transition and a reduced network of major chemical reactions, we present a semi-analytical prescription to estimate the abundances of O-bearing molecules in the diffuse ISM. We show that predictions based on our prescription are in good agreement with the estimates obtained using the MEUDON PDR code which utilizes the full reaction network. We investigate the dependence of the relative abundances of $\rm OH/H\, I$ and $\rm OH/H_2$ on the variations of physical conditions i.e. the metallicity, number density (n), cosmic ray ionization rate (ζ), and strength of UV field (χ) in the medium. We find that the $\rm OH/H\, I$ abundances observed in the Galactic ISM can be reproduced by models with n ~ 50 cm^-3, χ ~ 1 (Mathis field), and ζ ~ 3 × 10^-17 s^-1, with a variation of about 1 dex allowed around these values. Using the constrained $\rm H_2$ column density distribution function at z ~ 3, we estimate the $\rm OH$ column density distribution function and discuss future prospects with the upcoming large radio absorption line surveys.

We study the gravitational radiation emitted during the scattering of two spinless bodies in the post-Minkowskian effective field theory approach. We derive the conserved stress-energy tensor linearly coupled to gravity and the classical probability amplitude of graviton emission at leading and next-to-leading order in the Newton's constant G . The amplitude can be expressed in compact form as one-dimensional integrals over a Feynman parameter involving Bessel functions. We use it to recover the leading-order radiated angular momentum expression. Upon expanding it in the relative velocity between the two bodies v , we compute the total four-momentum radiated into gravitational waves at leading-order in G and up to an order v^{, 8} finding agreement with what was recently computed using scattering amplitude methods. Our results also allow us to investigate the zero frequency limit of the emitted energy spectrum.

The Method of Moments is a powerful framework to disentangle the relative contributions of amplitudes of a specific process to its various phase space regions. We apply this method to carry out a fully differential analysis of the Higgs decay channel h → 4ℓ and constrain gauge-Higgs coupling modifications parametrised by dimension-six effective operators. We find that this analysis approach provides very good constraints and minimises degeneracies in the parameter space of the effective theory. By combining the decay h → 4ℓ with Higgs-associated production processes, Wh and Zh, we obtain the strongest reported bounds on anomalous gauge-Higgs couplings.

We offer an exact analytical equation for the void central region. We show that the central density is solely determined by the amplitude of the initial perturbation. Our results suggest that N-body simulations somewhat overestimate the emptiness of voids: the majority of them should have the central underdensity $\delta _\mathrm{ c} \gt -73{{\ \rm per\ cent}}$ , and there should be almost no voids with $\delta _\mathrm{ c} \lt -88{{\ \rm per\ cent}}$. The central region of a void is a part of an open Friedmann's 'universe', and its evolution differs drastically from the Universe evolution: there is a long stage when the curvature term dominates that prevents the formation of galaxy clusters and massive galaxies inside voids. The density profile in the void centre should be very flat. We discuss some void models obtained by N-body simulations and offer some ways to improve them. We also show that the dark energy makes the voids less underdense.

We consider matter density effects in theories with a false ground state. Large and dense systems, such as stars, can destabilize a metastable minimum and allow for the formation of bubbles of the true minimum. We derive the conditions under which these bubbles form, as well as the conditions under which they either remain confined to the dense region or escape to infinity. The latter case leads to a phase transition in the universe at star formation. We explore the phenomenological consequences of such seeded phase transitions.

We report the serendipitous detection of an H₂-bearing damped Lyα absorber at z = 0.576 in the spectrum of the QSO J0111-0316 in the Cosmic Ultraviolet Baryon Survey. Spectroscopic observations from Hubble Space Telescope-COS in the far-ultraviolet reveal a damped absorber with log[N(H I)/cm^-2] = 20.1 ± 0.2 and log[N(H₂)/cm^-2] $={18.97}_{-0.06}^{+0.05}$ . The diffuse molecular gas is found in two velocity components separated by Δ ν ≍ 60 km s^-1, with >99.9% of the total H₂ column density concentrated in one component. At a metallicity of ≍50% of solar, there is evidence for Fe enhancement and dust depletion, with a dust-to-gas ratio κ_O ≍ 0.4. A galaxy redshift survey conducted with IMACS and LDSS-3C on Magellan reveals an overdensity of nine galaxies at projected distance d ≤ 600 proper kpc (pkpc) and line-of-sight velocity offset Δ ν_g ≤ 300 km s^-1 from the absorber. The closest is a massive, early-type galaxy at d = 41 pkpc that contains ≍70% of the total stellar mass identified at d ≤ 310 pkpc of the H₂ absorber. The close proximity of the H₂-bearing gas to the quiescent galaxy and the Fe-enhanced chemical abundance pattern of the absorber suggest a physical connection, in contrast to a picture in which DLAs are primarily associated with gas-rich dwarfs. This case study illustrates that deep galaxy redshift surveys are needed to gain insight into the diverse environments that host dense and potentially star-forming gas. * Based on data gathered with the 6.5 m Magellan Telescopes located at Las Campanas Observatory and the NASA/ESA Hubble Space Telescope operated by the Space Telescope Science Institute and the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-26555.

On-shell scattering amplitudes have proven to be useful tools for tackling the two-body problem in general relativity. This thesis outlines how to compute relevant classical observables that are themselves on-shell, directly from amplitudes; examples considered are the momentum impulse, total radiated momentum, and angular impulse for spinning particles. As applications we derive results relevant for black hole physics, computing in the post-Minkowskian expansion of GR, and construct a worldsheet effective action for the leading spin interactions of Kerr black holes.

We study the approach to scaling in axion string networks in the radiation era, through measuring the root-mean-square velocity v as well as the scaled mean string separation x . We find good evidence for a fixed point in the phase-space analysis in the variables (x ,v ), providing a strong indication that standard scaling is taking place. We show that the approach to scaling can be well described by a two parameter velocity-one-scale (VOS) model, and show that the values of the parameters are insensitive to the initial state of the network. The string length has also been commonly expressed in terms of a dimensionless string length density ζ , proportional to the number of Hubble lengths of string per Hubble volume. In simulations with initial conditions far from the fixed point ζ is still evolving after half a light-crossing time, which has been interpreted in the literature as a long-term logarithmic growth. We show that all our simulations, even those starting far from the fixed point, are accounted for by a VOS model with an asymptote of ζ_*=1.20 ±0.09 (calculated from the string length in the cosmic rest frame) and v_*=0.609 ±0.014 .

Light axionlike particles occur in many theories of beyond-Standard-Model physics, and may make up some or all of the Universe's dark matter. One of the ways they can couple to the Standard Model is through the electromagnetic F_{μ ν}F^{∼μ ν} portal, and there is a broad experimental program, covering many decades in mass range, aiming to search for axion dark matter via this coupling. In this paper, we derive limits on the absorbed power, and coupling sensitivity, for a broad class of such searches. We find that standard techniques, such as resonant cavities and dielectric haloscopes, can achieve O (1 )-optimal axion-mass-averaged signal powers, for given volume and magnetic field. For low-mass (frequency ≪GHz ) axions, experiments using static background magnetic fields generally have suppressed sensitivity; we discuss the physics of this limitation, and propose experimental methods to avoid it, such as microwave up-conversion experiments. We also comment on the detection of other forms of dark matter, including dark photons, as well as the detection of relativistic hidden-sector particles.

We combine orbital information from N-body simulations with an analytic model for star formation quenching and SDSS observations to infer the differential effect of the group/cluster environment on star formation in satellite galaxies. We also consider a model for gas stripping, using the same input supplemented with H I fluxes from the ALFALFA survey. The models are motivated by and tested on the Hydrangea cosmological hydrodynamical simulation suite. We recover the characteristic times when satellite galaxies are stripped and quenched. Stripping in massive ($M_{\rm vir}\sim 10^{14.5}\, {\rm M}_\odot$) clusters typically occurs at or just before the first pericentric passage. Lower mass ($\sim 10^{13.5}\, {\rm M}_\odot$) groups strip their satellites on a significantly longer (by $\sim 3\, {\rm Gyr}$) time-scale. Quenching occurs later: Balmer emission lines typically fade $\sim 3.5\, {\rm Gyr}$ ($5.5\, {\rm Gyr}$) after first pericentre in clusters (groups), followed a few hundred Myr later by reddenning in (g - r) colour. These 'delay time-scales' are remarkably constant across the entire satellite stellar mass range probed (~10^9.5-$10^{11}\, {\rm M}_\odot$), a feature closely tied to our treatment of 'group pre-processing'. The lowest mass groups in our sample ($\sim 10^{12.5}\, {\rm M}_\odot$) strip and quench their satellites extremely inefficiently: typical time-scales may approach the age of the Universe. Our measurements are qualitatively consistent with the 'delayed-then-rapid' quenching scenario advocated for by several other studies, but we find significantly longer delay times. Our combination of a homogeneous analysis and input catalogues yields new insight into the sequence of events leading to quenching across wide intervals in host and satellite mass.

We give a double copy construction for the symmetries of the self-dual sectors of Yang-Mills (YM) and gravity, in the light-cone formulation. We find an infinite set of double copy constructible symmetries. We focus on two families which correspond to the residual diffeomorphisms on the gravitational side. For the first one, we find novel non-perturbative double copy rules in the bulk. The second family has a more striking structure, as a non-perturbative gravitational symmetry is obtained from a perturbatively defined symmetry on the YM side.At null infinity, we find the YM origin of the subset of extended Bondi-Metzner-Sachs (BMS) symmetries that preserve the self-duality condition. In particular, holomorphic large gauge YM symmetries are double copied to holomorphic supertranslations. We also identify the single copy of superrotations with certain non-gauge YM transformations that to our knowledge have not been previously presented in the literature.

We present the first determination of the hadronic decays of the lightest exotic J^{P C}=1^-+ resonance in lattice QCD. Working with SU(3) flavor symmetry, where the up, down and strange-quark masses approximately match the physical strange-quark mass giving m_π∼700 MeV , we compute finite-volume spectra on six lattice volumes which constrain a scattering system featuring eight coupled channels. Analytically continuing the scattering amplitudes into the complex-energy plane, we find a pole singularity corresponding to a narrow resonance which shows relatively weak coupling to the open pseudoscalar-pseudoscalar, vector-pseudoscalar and vector-vector decay channels, but large couplings to at least one kinematically closed axial-vector-pseudoscalar channel. Attempting a simple extrapolation of the couplings to physical light-quark mass suggests a broad π₁ resonance decaying dominantly through the b₁π mode with much smaller decays into f₁π , ρ π , η^′π and η π . A large total width is potentially in agreement with the experimental π₁(1564 ) candidate state observed in η π , η^′π , which we suggest may be heavily suppressed decay channels.

We present new near-infrared, JHK_s, period-luminosity relations (PLRs) for RR Lyrae variables in the Messier 53 (M53 or NGC 5024) globular cluster. Multi-epoch JHK_s observations, obtained with the WIRCam instrument on the 3.6 m Canada-France-Hawaii Telescope, are used for the first time to estimate precise mean magnitudes for 63 RR Lyrae stars in M53 including 29 fundamental-mode (RRab) and 34 first-overtone mode (RRc) variables. The JHK_s-band PLRs for RR Lyrae stars are best constrained for RRab types with a minimal scatter of 22, 23, and 19 mmag, respectively. The combined sample of RR Lyrae is used to derive the K_s-band PLR, ${K}_{s}=-2.303(0.063)\mathrm{log}P+15.212(0.016)$ ,exhibiting a 1σ dispersion of only 0.027 mag. Theoretical period-luminosity-metallicity (PLZ) relations are used to predict parallaxes for 400 Galactic RR Lyrae, resulting in a median parallax zero-point offset of -7 ± 3 μas in Gaia Early Data Release 3 (EDR3), which increases to 22 ± 2 μas if the parallax corrections are applied. We also estimate a robust distance modulus, μ_M53 = 16.403 ± 0.024 (statistical) ± 0.033 (systematic) mag, to M53 based on theoretical calibrations. Homogeneous and precise mean magnitudes for RR Lyrae in M53 together with similar literature data for M3, M4, M5, and ω Cen are used to empirically calibrate a new RR Lyrae ${\mathrm{PLZ}}_{{K}_{s}}$ relation, ${K}_{s}=-0.848(0.007)\,-2.320(0.006)\mathrm{log}P+0.166(0.011)[\mathrm{Fe}/{\rm{H}}]$ ,anchored with Gaia EDR3 distances and theoretically predicted relations, and to simultaneously estimate precise RR Lyrae-based distances to these globular clusters.

We present an effective model for the one-dimensional Lyman-α flux power spectrum far above the baryonic Jeans scale. The main new ingredient is constituted by a set of two parameters that encode the impact of small, highly non-linear scales on the one-dimensional power spectrum on large scales, where it is measured by BOSS. We show that, by marginalizing over the model parameters that capture the impact of the intergalactic medium, the flux power spectrum from both simulations and observations can be described with high precision. The model displays a degeneracy between the neutrino masses and the (unknown, in our formalism) normalization of the flux power spectrum. This degeneracy can be lifted by calibrating one of the model parameters with simulation data, and using input from Planck CMB data. We demonstrate that this approach can be used to extract bounds on the sum of neutrino masses with comparably low numerical effort, while allowing for a conservative treatment of uncertainties from the dynamics of the intergalactic medium. An explorative analysis yields an upper bound of 0.16eV at 95% C.L. when applied to BOSS data at 3 ≤ z ≤ 4.2. We also forecast that if the systematic and statistical errors will be reduced by a factor two the upper bound will become 0.1eV at 95% C.L, and 0.056eV when assuming a 1% error.

Nonzero topological charge is prohibited in the chiral limit of continuum gauge-fermion systems because any unpaired instanton would create a zero mode of the Dirac operator. On the lattice, however, the geometric Q_geom=⟨F F ∼ ⟩/32 π² definition of the topological charge does not necessarily vanish in the chiral limit even when the gauge fields are smoothed for example with gradient flow. Small vacuum fluctuations (dislocations) not seen by the fermions may be promoted to instantonlike objects by the gradient flow. We demonstrate that these artifacts of the flow cause the gradient flow renormalized gauge coupling to increase and appear to run faster. In step-scaling studies such strong coupling artifacts contribute a term that might not follow perturbative scaling. The usual a /L →0 continuum limit extrapolations can hence lead to incorrect results. In this paper we investigate these topological lattice artifacts in the massless SU(3) 10-flavor system with domain wall fermions and the massless 8-flavor system with staggered fermions. For both systems we observe that in the range of strong coupling Symanzik gradient flow exhibits more lattice artifacts compared to Wilson gradient flow. We demonstrate how this artifact impacts the determination of the renormalized gauge coupling and the step-scaling β function.

In this paper we analyze the spectrum of the primordial gravitational waves (GWs) predicted in the Standard Model*Axion*Seesaw*Higgs portal inflation (SMASH) model, which was proposed as a minimal extension of the Standard Model that addresses five fundamental problems of particle physics and cosmology (inflation, baryon asymmetry, neutrino masses, strong CP problem, and dark matter) in one stroke. The SMASH model has a unique prediction for the critical temperature of the second order Peccei-Quinn (PQ) phase transition T_c ~ 10⁸ GeV up to the uncertainty in the calculation of the axion dark matter abundance, implying that there is a drastic change in the equation of state of the universe at that temperature. Such an event is imprinted on the spectrum of GWs originating from the primordial tensor fluctuations during inflation and entering the horizon at T ~ T_c, which corresponds to f ~ 1 Hz, pointing to a best frequency range covered by future space-borne GW interferometers. We give a precise estimation of the effective relativistic degrees of freedom across the PQ phase transition and use it to evaluate the spectrum of GWs observed today. It is shown that the future high sensitivity GW experiment—ultimate DECIGO—can probe the nontrivial feature resulting from the PQ phase transition in this model.

Hexaquarks constitute a natural extension of complex quark systems, just as tetra- and pentaquarks do. To this end, the current status of $d^*(2380)$ in both experiment and theory is reviewed. Recent high-precision measurements in the nucleon-nucleon channel and analyses thereof have established $d^*(2380)$ as an indisputable resonance in the long-sought dibaryon channel. Important features of this $I(J^P) = 0(3^+)$ state are its narrow width and deep binding relative to the $\Delta(1232)\Delta(1232)$ threshold. Its decay branchings favor theoretical calculations predicting a compact hexaquark nature of this state. We review the current status of experimental and theoretical studies on $d^*(2380)$ as well as new physics aspects it may bring in future. In addition, we review the situation at the $\Delta(1232) N$ and $N^*(1440)N$ thresholds, where evidence for a number of resonances of presumably molecular nature has been found - similar to the situation in charmed and beauty sectors. Finally, we briefly discuss the situation of dibaryon searches in the flavored quark sectors. * This work has been supported by DFG (CL 214/3-3). H. Cl. appreciates the support by the Munich Institute for Astro- and Particle Physics (MIAPP) which is funded by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) under Germany's Excellence Strategy - EXC-2094 - 390783311

We transform the metric of an isolated matter source in the multipolar post-Minkowskian approximation from harmonic (de Donder) coordinates to radiative Newman-Unti (NU) coordinates. To linearized order, we obtain the NU metric as a functional of the mass and current multipole moments of the source, valid all-over the exterior region of the source. Imposing appropriate boundary conditions we recover the generalized Bondi-van der Burg-Metzner-Sachs residual symmetry group. To quadratic order, in the case of the mass-quadrupole interaction, we determine the contributions of gravitational-wave tails in the NU metric, and prove that the expansion of the metric in terms of the radius is regular to all orders. The mass and angular momentum aspects, as well as the Bondi shear, are read off from the metric. They are given by the radiative quadrupole moment including the tail terms.

We present an expanded sample of 75 Milky Way Cepheids with Hubble Space Telescope (HST) photometry and Gaia EDR3 parallaxes, which we use to recalibrate the extragalactic distance ladder and refine the determination of the Hubble constant. All HST observations were obtained with the same instrument (WFC3) and filters (F555W, F814W, F160W) used for imaging of extragalactic Cepheids in Type Ia supernova (SN Ia) hosts. The HST observations used the WFC3 spatial scanning mode to mitigate saturation and reduce pixel-to-pixel calibration errors, reaching a mean photometric error of 5 millimags per observation. We use new Gaia EDR3 parallaxes, greatly improved since DR2, and the period-luminosity (P-L) relation of these Cepheids to simultaneously calibrate the extragalactic distance ladder and to refine the determination of the Gaia EDR3 parallax offset. The resulting geometric calibration of Cepheid luminosities has 1.0% precision, better than any alternative geometric anchor. Applied to the calibration of SNe Ia, it results in a measurement of the Hubble constant of 73.0 ± 1.4 km s^-1 Mpc^-1, in good agreement with conclusions based on earlier Gaia data releases. We also find the slope of the Cepheid P-L relation in the Milky Way, and the metallicity dependence of its zero-point, to be in good agreement with the mean values derived from other galaxies. In combination with the best complementary sources of Cepheid calibration, we reach 1.8% precision and find H₀ = 73.2 ± 1.3 km s^-1 Mpc^-1, a 4.2σ difference with the prediction from Planck CMB observations under ΛCDM. We expect to reach ∼1.3% precision in the near term from an expanded sample of ∼40 SNe Ia in Cepheid hosts.

We propose a novel Bayesian method to analytically continue observables to real baryochemical potential μ_B in finite density QCD. Taylor coefficients at μ_B=0 and data at imaginary chemical potential μ_B^I are treated on equal footing. We consider two different constructions for the Padé approximants, the classical multipoint Padé approximation and a mixed approximation that is a slight generalization of a recent idea in Padé approximation theory. Approximants with spurious poles are excluded from the analysis. As an application, we perform a joint analysis of the available continuum extrapolated lattice data for both pseudocritical temperature T_c at μ_B^I from the Wuppertal-Budapest Collaboration and Taylor coefficients κ₂ and κ₄ from the HotQCD Collaboration. An apparent convergence of [p /p ] and [p /p +1 ] sequences of rational functions is observed with increasing p . We present our extrapolation up to μ_B≈600 MeV .

We consider the use of quantum-limited mechanical force sensors to detect ultralight (sub-meV) dark matter (DM) candidates which are weakly coupled to the standard model. We show that mechanical sensors with masses around or below the milligram scale, operating around the standard quantum limit, would enable novel searches for DM with natural frequencies around the kHz scale. This would complement existing strategies based on torsion balances, atom interferometers, and atomic clock systems.

We discuss a method that employs a multilayer perceptron to detect deviations from a reference model in large multivariate datasets. Our data analysis strategy does not rely on any prior assumption on the nature of the deviation. It is designed to be sensitive to small discrepancies that arise in datasets dominated by the reference model. The main conceptual building blocks were introduced in D'Agnolo and Wulzer (Phys Rev D 99 (1), 015014. doi.org/10.1103/PhysRevD.99.015014. arXiv:1806.02350 [hep-ph], 2019). Here we make decisive progress in the algorithm implementation and we demonstrate its applicability to problems in high energy physics. We show that the method is sensitive to putative new physics signals in di-muon final states at the LHC. We also compare our performances on toy problems with the ones of alternative methods proposed in the literature.

We explore how to mitigate the clustering distortions in Lyman α emitter (LAE) samples caused by the misidentification of the Lyman α ( $\rm {Ly}\,\alpha$ ) wavelength in their $\rm {Ly}\,\alpha$ line profiles. We use the $\rm {Ly}\,\alpha$ line profiles from our previous LAE theoretical model that includes radiative transfer in the interstellar and intergalactic mediums. We introduce a novel approach to measure the systemic redshift of LAEs from their $\rm {Ly}\,\alpha$ line using neural networks. In detail, we assume that for a fraction of the whole LAE population their systemic redshift is determined precisely through other spectral features. We then use this subset to train a neural network that predicts the $\rm {Ly}\,\alpha$ wavelength given an $\rm {Ly}\,\alpha$ line profile. We test two different training sets: (i) the LAEs are selected homogeneously and (ii) only the brightest LAE is selected. In comparison with previous approaches in the literature, our methodology improves significantly the accuracy in determining the $\rm {Ly}\,\alpha$ wavelength. In fact, after applying our algorithm in ideal $\rm {Ly}\,\alpha$ line profiles, we recover the clustering unperturbed down to $1\, {\rm cMpc}\, h^{-1}$ . Then, we test the performance of our methodology in realistic $\rm {Ly}\,\alpha$ line profiles by downgrading their quality. The machine learning technique using the uniform sampling works well even if the $\rm {Ly}\,\alpha$ line profile quality is decreased considerably. We conclude that LAE surveys such as HETDEX would benefit from determining with high accuracy the systemic redshift of a subpopulation and applying our methodology to estimate the systemic redshift of the rest of the galaxy sample.

The relationship between a galaxy's properties and its circumgalactic medium (CGM) provides a unique view of how galaxies evolve. We present an interesting edge-on (i = 86°) disc galaxy (G1547) where the CGM is probed by a background quasar at a distance of 84 kpc and within 10° of the galaxy major axis. G1547 does not have any detectable CGM absorption down to stringent limits, covering H I (EW_r <0.02 Å, log(N(H I)/cm^-2) < 12.6) and a range of low and high ionization absorption lines (O I, C II, N II, Si II, C III, N III, Si III, C IV, Si IV, N V, and O VI). This system is rare, given the covering fraction of $1.00_{-0.04}^{+0.00}$ for sub-L* galaxies within 50-100 kpc of quasar sightlines. G1547 has a low star formation rate (SFR, 1.1 M_⊙ yr^-1), specific SFR (sSFR, 1.5 × 10^-10 yr^-1), and Σ_SFR (0.06 M_⊙ yr^-1 kpc^-2) and does not exhibit active galactic nucleus or star-formation-driven outflows. Compared to the general population of galaxies, G1547 is in the green valley and has an above average metallicity with a negative gradient. When compared to other H I absorption-selected galaxies, we find that quiescent galaxies with log(sSFR/yr^-1) < -11 have a low probability (4/12) of possessing detectable H I in their CGM, while all galaxies (40/40) with log(sSFR/yr^-1) > -11 have H I absorption. We conclude that sSFR is a good indicator of the presence of H I CGM. Interestingly however, G1547 is the only galaxy with log(sSFR/yr^-1) > -11 that has no detectable CGM. Given the properties of G1547, and its absent CGM, it is plausible that G1547 is undergoing quenching due to a lack of accreting fuel for star formation, with an estimated quenching time-scale of 4 ± 1 Gyr. G1547 provides a unique perspective into the external mechanisms that could explain the migration of galaxies into the green valley.

We present a next-to-next-to-leading (fifth or NNLO) order calculation for the covariance matrix of the matter power spectrum, taking into account the effect of survey window functions. Using the grid-based calculation scheme for the standard perturbation theory, GridSPT, we quickly generate multiple realizations of the nonlinear density fields to fifth order in perturbation theory, then estimate the power spectrum and the covariance matrix from the sample. To the end, we have obtained the non-Gaussian covariance originated from the one-loop trispectrum without explicitly computing the trispectrum. By comparing the GridSPT calculations with the N -body results, we show that NNLO GridSPT result reproduces the N -body results on quasilinear scales, where SPT accurately models nonlinear matter power spectrum. Incorporating the survey window function effect to GridSPT is rather straightforward, and the resulting NNLO covariance matrix also matches well with the N -body results.

We investigate the spatially resolved morphology of galaxies in the early Universe. We consider a typical redshift z = 6 Lyman break galaxy, 'Althæa', from the SERRA hydrodynamical simulations. We create mock rest-frame ultraviolet (UV), optical, and far-infrared observations, and perform a two-dimensional morphological analysis to deblend the galaxy disc from substructures (merging satellites or star-forming regions). We find that the [C II]158 μm emitting region has an effective radius 1.5-2.5 times larger than the optical one, consistent with recent observations. This [C II] halo in our simulated galaxy arises as the joint effect of stellar outflows and carbon photoionization by the galaxy UV field, rather than from the emission of unresolved nearby satellites. At the typical angular resolution of current observations (≳ 0.15 arcsec) only merging satellites can be detected; detection of star-forming regions requires resolutions of ≲ 0.05 arcsec. The [C II]-detected satellite has a 2.5-kpc projected distance from the galaxy disc, whereas the star-forming regions are embedded in the disc itself (distance ≲ 1 kpc). This suggests that multicomponent systems reported in the literature, which have separations ≳ 2 kpc, are merging satellites, rather than galactic substructures. Finally, the star-forming regions found in our mock maps follow the local L_{[C II]}-SFR_UV relation of galaxy discs, although sampling the low-luminosity, low-SFR tail of the distribution. We show that future James Webb Space Telescope observations, bridging UV and [C II] data sets, will be exceptionally suited to characterize galaxy substructures, thanks to their exquisite spatial resolution and sensitivity to both low-metallicity and dust-obscured regions that are bright at infrared wavelengths.

We investigate the reliability of standard N-body simulations by modeling of the well-known Hernquist halo with the help of GADGET-2 code (which uses the tree algorithm to calculate the gravitational force) and ph4 code (which uses the direct summation). Comparing the results, we find that the core formation in the halo center (which is conventionally considered as the first sign of numerical effects, to be specific, of the collisional relaxation) has nothing to do with the collisional relaxation, being defined by the properties of the tree algorithm. This result casts doubts on the universally adopted criteria of the simulation reliability in the halo center.

Though we use a halo model, which is theoretically proved to be stationary and stable, a sort of numerical 'violent relaxation' occurs. Its properties suggest that this effect is highly likely responsible for the central cusp formation in cosmological modeling of the large-scale structure, and then the 'core-cusp problem' is no more than a technical problem of N-body simulations.

We have used the Australian Square Kilometre Array Pathfinder (ASKAP) radio telescope to search for intervening 21 cm neutral hydrogen (H I) absorption along the line of sight to 53 bright radio continuum sources. Our observations are sensitive to H I column densities typical of Damped Lyman Alpha absorbers (DLAs) in cool gas with an H I spin temperature below about 300-500 K. The six-dish Boolardy Engineering Test Array (BETA) and twelve-antenna Early Science array (ASKAP-12) covered a frequency range corresponding to redshift 0.4 < z < 1.0 and 0.37 < z < 0.77, respectively, for the H I line. Fifty of the 53 radio sources observed have reliable optical redshifts, giving a total redshift path Δz = 21.37. This was a spectroscopically untargeted survey, with no prior assumptions about the location of the lines in redshift space. Four intervening H I lines were detected, two of them new. In each case, the estimated H I column density lies above the DLA limit for H I spin temperatures above 50-80 K, and we estimate a DLA number density at redshift z ∼ 0.6 of $n(z)=0.19^{+0.15 }_{ -0.09}$ . This value lies somewhat above the general trend of n(z) with redshift seen in optical DLA studies. Although the current sample is small, it represents an important proof of concept for the much larger 21 cm First Large Absorption Survey in H I (FLASH) project to be carried out with the full 36-antenna ASKAP telescope, probing a total redshift path $\Delta z\sim \, 50,000$ .

This document presents the physics case and ancillary studies for the proposed CODEX-b long-lived particle (LLP) detector, as well as for a smaller proof-of-concept demonstrator detector, CODEX-<inline-formula id="IEq1"><mml:math><mml:mi>β</mml:mi></mml:math></inline-formula>, to be operated during Run 3 of the LHC. Our development of the CODEX-b physics case synthesizes 'top-down' and 'bottom-up' theoretical approaches, providing a detailed survey of both minimal and complete models featuring LLPs. Several of these models have not been studied previously, and for some others we amend studies from previous literature: In particular, for gluon and fermion-coupled axion-like particles. We moreover present updated simulations of expected backgrounds in CODEX-b's actively shielded environment, including the effects of shielding propagation uncertainties, high-energy tails and variation in the shielding design. Initial results are also included from a background measurement and calibration campaign. A design overview is presented for the CODEX-<inline-formula id="IEq2"><mml:math><mml:mi>β</mml:mi></mml:math></inline-formula> demonstrator detector, which will enable background calibration and detector design studies. Finally, we lay out brief studies of various design drivers of the CODEX-b experiment and potential extensions of the baseline design, including the physics case for a calorimeter element, precision timing, event tagging within LHCb, and precision low-momentum tracking.

Classical Cepheid and RR Lyrae variables are radially pulsating stars that trace young and old-age stellar populations, respectively. These classical pulsating stars are the most sensitive probes for the precision stellar astrophysics and the extragalactic distance measurements. Despite their extensive use as standard candles thanks to their well-defined Period–Luminosity relations, distance measurements based on these objects suffer from their absolute primary calibrations, metallicity effects, and other systematic uncertainties. Here, I present a review of classical Cepheid, RR Lyrae and type II Cepheid variables starting with a historical introduction and describing their basic evolutionary and pulsational properties. I will focus on recent theoretical and observational efforts to establish absolute scale for these standard candles at multiple wavelengths. The application of these classical pulsating stars to high-precision cosmic distance scale will be discussed along with observational systematics. I will summarize with an outlook for futher improvements in our understanding of these classical pulsators in the upcoming era of extremely large telescopes.