We study the axion-photon conversion process in pulsar binary systems with high Shapiro time delay. In these binary systems, the orbital plane is nearly parallel to the line of sight. When the companion star is positioned between the pulsar and the Earth, the pulsar radiation beam will pass through the companion’s magnetic field, potentially leading to axion-photon conversion that affects the intensity and linear polarization of the photons. The advantage of using such systems for axion or axionlike particle (ALP) research is that the intrinsic intensity and polarization state of the source photons can be well determined. This work analyzes the axion-photon conversion and the magnetic field along the photon path, establishing the corresponding model and solving it numerically. We choose PSR J1614-2230 and PSR J1910-5959A for our study. By assuming the companion’s magnetic field, magnetic axis angle, and detector sensitivity, we discuss the feasibility of using high Shapiro delay binary systems to constrain the axion/ALP parameter space. We find that the upper limits derived from these two sources are weaker then existing constraints. However, considering the higher reliability, the method proposed in this work is still valuable. As more suitable samples and richer observational results are discovered, further constraints on the axion parameters could be strengthened.

Tensor network methods have demonstrated their suitability for the study of equilibrium properties of lattice gauge theories, even close to the continuum limit. We use them in an out-of-equilibrium scenario, much less explored so far, by simulating the real-time collisions of composite mesons in the lattice Schwinger model. Constructing wave-packets of vector mesons at different incoming momenta, we observe the opening of the inelastic channel in which two heavier mesons are produced and identify the momentum threshold. To detect the products of the collision in the strong coupling regime we propose local quantitites that could be measured in current quantum simulation platforms.

This article presents constraints on dark-matter-electron interactions obtained from the first underground data-taking campaign with multiple SuperCDMS HVeV detectors operated in the same housing. An exposure of $7.63\mathrm{g}\text{−}\mathrm{days}$ is used to set upper limits on the dark-matter-electron scattering cross section for dark matter masses between 0.5 and $1000\mathrm{MeV}/c^2$, as well as upper limits on dark photon kinetic mixing and axionlike particle axioelectric coupling for masses between 1.2 and $23.3\mathrm{eV}/c^2$. Compared to an earlier HVeV search, sensitivity was improved as a result of an increased overburden of 225 meters of water equivalent, an anticoincidence event selection, and better pile-up rejection. In the case of dark-matter-electron scattering via a heavy mediator, an improvement by up to a factor of 25 in cross section sensitivity was achieved.

In a spherically symmetric and static spacetime of a compact object, such as that of a Schwarzschild black hole, the light-ring is a two-sphere where photons experience the only possible circular orbits. As a “gedanken experiment,” we imagine an advanced civilization able to populate the light-ring of a nonrotating black hole of mass $M$ with photons having a fine-tuned impact parameter that allows their orbits to be exactly circular with radius $r=3M$. As the number of photons in the light-ring increases in time, its mass will no longer be negligible, and hence it will impact on the background spacetime; that is, it will “self-gravitate.” We here consider two different routes to assign a nonzero mass to the light-ring that are either based on a discrete concentration of photons on a specific radial location or on a suitable distribution of photons in a given region. In both cases, and using the Einstein equations, we find that the inclusion of the energy from the accumulated photons leads to the generation of new light-rings. Such new light-rings can either appear at well-defined but discrete locations, or be fused in a well-defined region. In either case, we show that such light-ring configurations are dynamically unstable and a small perturbation, either via the inclusion of an additional photon onto the light-ring or via the absorption of a photon by the black hole, leads to a catastrophic destruction of the light-ring structures.

We train a deep neural network (DNN) to output rates of dark matter (DM) induced electron excitations in silicon and germanium detectors. Our DNN provides a massive speedup of around 5 orders of magnitude relative to existing methods (i.e., qedark-eft), allowing for extensive parameter scans in the event of an observed DM signal. The network is also lighter and simpler to use than alternative computational frameworks based on a direct calculation of the DM-induced excitation rate.

In this paper we investigate the code properties of holographic fractal geometries initiated in Pastawski et al. [Phys. Rev. X 7, 021022 (2017)]. We study reconstruction wedges in ${\mathrm{AdS}}_3/{\mathrm{CFT}}_2$ for black hole backgrounds, which are in qualitative agreement with the vacuum-AdS approximation using generalized entanglement entropy in Bao et al. [Phys. Rev. D 107, 066014 (2023)]. In higher dimensions, we study reconstruction wedges for the infinite, straight strip in ${\mathrm{AdS}}_{d+1}/{\mathrm{CFT}}_d$ and clarify the roles of “straight” and “infinite” in their code properties. Lastly, we comment on uberholography from the perspective of complexity transfer and one-shot holography.

In pursuit of a full-fledged theory of quantum gravity, operational approaches offer insights into quantum-gravitational effects produced by quantum superposition of different spacetimes not diffeomorphic to one another. Recent work applies this approach to superpose cylindrically identified Minkowski spacetimes (i.e., periodic boundary conditions) with different characteristic circumferences, where a two-level detector coupled to a quantum field residing in the spacetime exhibits resonance peaks in response at certain values of the superposed length ratios. Here, we extend this analysis to a superposition of cylindrically identified Rindler spacetimes, considering a two-level detector constantly accelerated in the direction orthogonal to the compact dimension. Similar to previous work, we find resonance peaks in the detector response at rational ratios of the superposed compactified lengths, which we observe to be accentuated by the acceleration of the detector. Furthermore, for the first time we confirm the detailed balance condition due to acceleration in a superposition of spacetimes, commensurate with the Unruh effect in a single spacetime state. The resonant structure of detector response in the presence of event horizons, for the first time observed in $3+1$ dimensions, may offer clues to the nature of black hole entropy in the full theory of quantum gravity.

Antiquark nuggets are hypothetical compact composite objects conjectured to account for a significant fraction of dark matter in the Universe. In contrast to quark nuggets, these objects consist of antimatter. They may remain undetected if they possess a sufficiently small cross section relative to their mass. In this paper, we investigate the allowed region in the parameter space of this model that is consistent with the observed neutrino flux from the Sun and the Earth, and the nonobservation of seismic events with specific signatures of dark matter particles. We found the allowed values of the antibaryon charge number in this model to be in the interval $2\times {10}^{24}<A<8\times {10}^{25}$, while the probability of nucleon annihilation upon collisions with the antiquark core is constrained by $0.1\lesssim \kappa <0.25$. These values of $A$ and $\kappa$ are, however, constrained by the IceCube experiment and nonobservation of impacts of antiquark nuggets on humans. Although very large values of the antibaryon charge, $A>{10}^{33}$, are not fully excluded by the present study, we show that they conflict with the nonobservation of rare catastrophic explosionlike events on the Earth.

We investigate the effects of ultralight axions (ULAs) on the differential brightness temperature fluctuations of neutral hydrogen at the postreionization stage. Unique structure suppression features under the influence of ULAs are studied from angular correlations of the neutral hydrogen signals observed at different frequencies. Moreover, ULAs can behave like dark energy or dark matter at different mass regimes, implying that the fraction of the ULA energy density would be correlated with the sum of neutrino masses and the parameters of the dark energy equation of state for dark matter and dark energy like ULAs, respectively. We have explored the parameter space for the ULA physics and possible degeneracies among dark energy, neutrinos, and ULAs using the theoretical angular correlation functions expected from future intensity mapping surveys.

Neutron star properties depend on both nuclear physics and astrophysical processes, and thus observations of neutron stars offer constraints on both large-scale astrophysics and the behavior of cold, dense matter. In this study, we use astronomical data to jointly infer the universal equation of state of dense matter along with two distinct astrophysical populations: Galactic neutron stars observed electromagnetically and merging neutron stars in binaries observed with gravitational waves. We place constraints on neutron star properties and quantify the extent to which they are attributable to macrophysics or microphysics. We confirm previous results indicating that the Galactic and merging neutron stars have distinct mass distributions. The inferred maximum mass of both Galactic neutron stars, $M_{\mathrm{pop},\mathrm{EM}}=2.05_{-0.06}^{+0.11}{M}_{\odot }$ (median and 90% symmetric credible interval), and merging neutron star binaries, $M_{\mathrm{pop},\mathrm{GW}}=1.85_{-0.16}^{+0.39}{M}_{\odot }$, are consistent with the maximum mass of nonrotating neutron stars set by nuclear physics, $M_{\mathrm{TOV}}=2.28_{-0.21}^{+0.41}{M}_{\odot }$. The radius of a $1.4M_{\odot }$ neutron star is ${12.2}_{-0.9}^{+0.8}\mathrm{km}$, consistent with, though $\sim 20\%$ tighter than, previous results using an identical equation of state model. Even though observed Galactic and merging neutron stars originate from populations with distinct properties, there is currently no evidence that astrophysical processes cannot produce neutron stars up to the maximum value imposed by nuclear physics.

Polarimetric features during the prompt phase of gamma-ray bursts (GRBs) have been essential for elucidating the debated emission mechanisms and gaining insight into the inner structure of GRBs. However, the potential impact of photon-axionlike particle (ALP) mixing in extragalactic magnetic fields, leading to significant modifications to the initial polarization state, has been overlooked in discussions concerning prompt phase constraints. In this work, we first examine the statistical characteristics of linear polarization degree (${\mathrm{\Pi }}_L$) in GRBs, by utilizing data from polarimetric missions focusing on sub-MeV emissions. Our analysis, conducted with a restricted sample of GRBs spanning various redshifts, reveals a diverse distribution of ${\mathrm{\Pi }}_L$, which currently shows no correlation with the GRBs’ spectral parameters or properties of candidate host galaxies. We then explore alternations to the initial ${\mathrm{\Pi }}_L$ due to photon-ALP mixing within a domainlike structure of the intergalactic magnetic field (${\mathbf{B}}_{\mathrm{IGM}}$), considering various parameter sets associated with ALPs ($m_a$, $g_{a\gamma }$) and ${\mathbf{B}}_{\mathrm{IGM}}$. For ALPs with $m_a\lesssim {10}^{-14}\mathrm{eV}$, photon-ALP mixing decreases the polarization degree of initially fully polarized photons (${\mathrm{\Pi }}_{L_0}=1$) and induces polarization in initially unpolarized photons (${\mathrm{\Pi }}_{L_0}=0$). Significant alterations to ${\mathrm{\Pi }}_{L_0}$ are expected when the mixing term ${\mathrm{\Delta }}_{a\gamma }\equiv 1/2g_{a\gamma }{\mathbf{B}}_{\mathrm{IGM}}$ exceeds $1.5\times {10}^{-4}{\mathrm{Mpc}}^{-1}$. The primary feature of the final ${\mathrm{\Pi }}_L$ as a function of the source redshifts is that ${\mathrm{\Pi }}_L$ approaches a midrange value for a significant ${\mathrm{\Delta }}_{a\gamma }$ achieved when photons are emitted from high-redshift GRBs, regardless of the assumed initial ${\mathrm{\Pi }}_{L_0}$. Currently, the number of GRBs with both sub-MeV polarization measurement and redshift confirmation remains very limited. Half of the GRBs with available polarization data have ${\mathrm{\Pi }}_L$ being less than 30%. Certification of redshift for this subset of GRBs would further constrain the parameter space of low-mass ALPs or provide an independent means to determine the upper limit on ${\mathbf{B}}_{\mathrm{IGM}}$.

In this work, the soft rescattering parameters in the $B^{\pm }\to {\pi }^{\pm }{\pi }^{+}{\pi }^{-}$ and $B^{\pm }\to K^{\pm }{\pi }^{+}{\pi }^{-}$ decays with the light scalar meson $f_0(500)$ as the intermediate resonance are studied within the quantum chromodynamics (QCD) factorization. Considering the interference effect between $\rho (770{)}^0$ and $f_0(500)$, we utilize the experimentally more direct event yields for fitting and get the soft rescattering parameters $|{\rho }_k^{SP}|=3.29\pm 1.01$ and $|{\rho }_k^{PS}|=2.33\pm 0.73$ in $B\to PS$ and $B\to SP$ decays ($P$ and $S$ denote pseudoscalar and scalar mesons, respectively), respectively. We also study the branching ratios and $CP$ asymmetries in the decay modes involving other scalar mesons, including $f_0(980)$, $a_0(980)$, $a_0(1450)$ and $K_0^{*}(1430)$, to test the rationality of the values of $|{\rho }_k^{SP}|$ and $|{\rho }_k^{PS}|$. Meanwhile, the wealth of experimental data facilitate the examination of the forward-backward asymmetry induced $CP$ asymmetries (FB-CPAs), and the localized $CP$ asymmetries (LACPs). We investigate these asymmetries resulting from the interference between $\rho (770{)}^0$ and $f_0(500)$ for $B^{\pm }\to {\pi }^{\pm }{\pi }^{+}{\pi }^{-}$ and $B^{\pm }\to K^{\pm }{\pi }^{+}{\pi }^{-}$ decays when the invariant mass of ${\pi }^{+}{\pi }^{-}$ locates in the low-energy region $0.445\mathrm{GeV}<m_{\pi \pi }<0.795\mathrm{GeV}$. Our theoretical results of FB-CPAs and LACPs align with the experimental findings. We propose that the interference between $\rho (770{)}^0$ and $f_0(500)$ can be extended to other beauty and charmed mesons decays.

The bounds on parameters of the eV and higher scale Majorana sterile neutrinos from the $0\nu \beta \beta$ decay have been refined and updated. We present a simple and compact analytic expression for the bound in the $\mathrm{\Delta }{m}_{41}^2-{\sin }^{2}2{\theta }_{14}$ plane, which includes all relevant parameters. Dependencies of the bound on unknown $CP$ phases and the type of mass spectrum of light neutrinos (mass ordering and level of degeneracy) are studied in detail. We have computed the bounds using the latest and most stringent data from KamLAND-Zen. The projected constraints from future experiments are estimated. The obtained bounds are confronted with positive indications of the presence of sterile neutrinos as well as with the other existing bounds. The $0\nu \beta \beta$ decay results exclude the regions of parameters implied by BEST and Neutrino-4, and the regions indicated by LSND and MiniBooNE are in conflict with $0\nu \beta \beta$ decay results combined with ${\nu }_{\mu }$-disappearance bounds.

We explore the implications of symmetries that remain unbroken at the self-dual point $\tau =i$ in modular invariant theories. Assuming that (a) the three generations of lepton doublets transform as an irreducible representation of a finite modular group ${\mathrm{\Gamma }}_N$, and (b) the light neutrino masses arise from the Weinberg operator and are in modular form, we demonstrate that this setup yields a unique residual flavor symmetry or antisymmetry for the neutrinos, depending on the modular weight. In the antisymmetric case, one neutrino is always massless, and the other two can be degenerate if the mass matrix is real. These findings are independent of the level $N$. If the charged leptons are arranged to exhibit an appropriate residual symmetry from the same ${\mathrm{\Gamma }}_N$, they determine a column of the leptonic mixing matrix, leading to specific correlations between the mixing angles and the Dirac $CP$ phase. The presence of residual (anti)symmetries enables the application of standard flavor symmetry techniques to derive these predictions, and we scan all possible ${\mathrm{\Gamma }}_N$ satisfying condition (a). Most solutions yield $\mathcal{O}(1)$ entries in the fixed column, favoring relatively large lepton mixing.

We investigate the weak semileptonic decay of the ${\mathrm{\Omega }}_{ccb}^{+}\to {\mathrm{\Xi }}_{cc}^{++}\ell {\overline{\nu }}_{\ell }$, where a triply heavy baryon with spin $1/2$ decays into the observed doubly heavy baryon with spin $1/2$, using quantum chromodynamics (QCD) sum rule method in all lepton channels. We compute the six relevant vector and axial vector form factors entering the low energy matrix elements in full theory. The invariant form factors are building blocks, using the fit faction of which in terms of $q^2$ in whole physical region, we calculate the exclusive widths in three lepton channels. Our predictions may help the present and future experiments in the course of their search for doubly and triply heavy baryons.

Motivated by the first observation, to the best of our knowledge, of a doubly charmed tetraquark candidate $T_{cc}(3875{)}^{+}$, we perform a systematic calculation of the masses of some constituent diquarks and the doubly charmed tetraquark states from $1S$ to $2P$ excitations in a nonrelativistic constituent quark potential model. First, the mass of the charmed spin-1 diquark is predicted with $\sim 3500\mathrm{MeV}$, and the masses of the light “good” (spin-0 and isospin-0) and “bad” (spin-1 and isospin-1) antidiquark are predicted with $\sim 670\mathrm{MeV}$ and $\sim 840\mathrm{MeV}$, respectively. The mass difference between a light good and a light bad diquark is $\sim 170\mathrm{MeV}$, which is consistent with previous phenomenological analyses. The interaction between the charmed diquark and the light antidiquark is then modulated by the quark-antiquark potential in the model, and the mass spectra of doubly charmed tetraquarks from $1S$ to $2P$ excitations are calculated with the obtained masses of diquarks/antidiquarks and refitted parameters from $T_{cc}(3875{)}^{+}$ and $X(3872)$. The pattern of the mass spectra of doubly charmed tetraquarks is obtained explicitly. The $1S-1P$ and $1S-2S$ mass splittings of doubly charmed tetraquarks are about 410–430 MeV and 610–650 MeV, respectively, and this mass splittings pattern is similar to that for ordinary $D$ mesons. The mass splittings of doubly charmed tetraquarks with a good diquark is about 10–25 MeV higher than the corresponding mass splittings of doubly charmed tetraquarks with a bad diquark from $1S$ to $2P$ excitations. When $T_{cc}(3875{)}^{+}$ is assumed as a $I{J}^P=01^{+}$ ground doubly charmed tetraquark with a light good antidiquark, the next $P$-wave excited doubly charmed tetraquarks are predicted to have masses with an average 420–430 MeV higher. A $I{J}^P=10^{+}$ ground doubly charmed tetraquark $T_{cc}(3834)$ located around 3834 MeV is also expected.

We discuss the nonlocal generalization of the QCD chiral anomaly along the light cone and derive relations between twist-two, twist-three, and twist-four generalized parton distributions (GPDs) mediated by the anomaly. We further establish the connection to the “anomaly pole” in the GPD $\tilde{E}$ recently identified in the perturbative calculation of the Compton scattering amplitudes, and demonstrate its cancellation at the GPD level. Our work helps elucidate the previously unexplored connection between GPDs, the chiral anomaly, and the mass generation of the ${\eta }^{\prime }$ meson.

Liquid xenon time projection chambers (TPCs) detect both the scintillation photons and ionization electrons created by energy depositions within the liquid xenon (LXe) volume. Dual-phase (liquid-gas) xenon TPCs, which detect ionization electrons through proportional scintillation in a thin gas gap after extracting electrons through the liquid, are now widely used in the field of dark matter direct detection because of their low-energy detection capability and their ability to discriminate between electronic and nuclear recoils. In this paper, we demonstrate that a purely single-phase liquid xenon TPC which produces proportional scintillation directly in the liquid is still capable of discriminating between electronic and nuclear recoils at low energy that is relevant to dark matter direct detection and neutrino-nucleus coherent scattering experiments. Using the single-phase detector, we also investigate the delayed electrons which are a major background in liquid xenon experiments to search for light dark matter. We observed similar behaviors of delayed electrons and concluded that the liquid-gas interface in a dual-phase TPC is unlikely the major source of delayed single-electron background.

Using $(2.712\pm 0.014)\times {10}^9\psi (2S)$ events collected with the BESIII detector operating at the BEPCII, we search for the ${\eta }_c(2S)\to K^{+}{K}^{-}{\eta }^{\prime }$ decay. Its decay branching fraction is measured to be $(11.11\pm 4.67_{(\mathrm{stat})}\pm 1.82_{(\mathrm{syst})}\pm 4.24_{(\mathrm{extr})})\times {10}^{-4}$, where the first uncertainty is statistical, the second is systematic, and the third uncertainty is from the branching fraction of the $\psi (2S)\to \gamma {\eta }_c(2S)$ decay. The statistical significance is $2.8\sigma$. The upper limit on the product branching fraction $B[\psi (2S)\to \gamma {\eta }_c(2S)]\times B[{\eta }_c(2S)\to K^{+}{K}^{-}{\eta }^{\prime }]$ is set to be $0.94\times {10}^{-6}$ at 90% confidence level. In addition, the branching fractions of ${\chi }_{c1}\to K^{+}{K}^{-}{\eta }^{\prime }$ and ${\chi }_{c2}\to K^{+}{K}^{-}{\eta }^{\prime }$ are updated to be $(8.48\pm 0.10(\mathrm{stat})\pm 0.47(\mathrm{syst}))\times {10}^{-4}$ and $(1.53\pm 0.04(\mathrm{stat})\pm 0.08(\mathrm{syst}))\times {10}^{-4}$, respectively. The precision is improved by twofold.

Cotton gravity was recently introduced as a higher derivative extension of general relativity. The field equations of the theory involve the rank-3 Cotton tensor. Here we show that all solutions of the theory, including the black holes, have vanishing conserved charges, i.e. mass and angular momentum. This result implies that either the theory is unphysical since all the black holes carry the charges of the vacuum and can be created at no energy cost, or the theory has confinement of mass/energy and all other conserved quantities.