We investigate the influence of quark anomalous magnetic moments (AMMs) on the mass spectra of neutral pseudoscalar mesons ($\pi$, $K$, $\eta$, ${\eta }^{\prime }$) under external magnetic fields, finite temperatures, and quark chemical potentials using the three-flavor Nambu-Jona-Lasinio model. By incorporating AMMs at the quark level, we reveal that AMMs significantly alter the magnetic field dependence of constituent quark masses, inducing first-order phase transitions for light quarks at critical fields, while strange quarks exhibit nonmonotonic mass behavior. The inclusion of AMMs reshapes the QCD phase diagram, suppressing chiral transition temperatures, and the strong magnetic field shifts critical endpoints toward lower $\mu$ and higher $T$ without AMMs. The crossover phase transition without AMMs is replaced by a first-order transition with AMMs under strong fields. Moreover, the inverse magnetic catalysis (IMC) induced by the introduction of AMMs qualitatively aligns with the predictions of lattice QCD (LQCD) for the dependence of phase transition temperature on the magnetic field. For mesons, a larger AMM triggers abrupt mass collapses and enhances flavor spitting at zero $\mu$ and $T$ and accelerates chiral restoration for $K$ and $\eta$ mesons via thresholds tied to strange quark masses in finite $\mu$ and $T$. These findings underscore AMMs’ critical role in reconciling effective model predictions with LQCD results, particularly in reproducing IMC and explaining phase transition dynamics.

The quantum speed limits (QSLs) set fundamental lower bounds on the time required for a quantum system to evolve from a given initial state to a final state. In this work, we investigate $CP$ violation and the mass ordering problem of neutrino oscillations in matter using the QSL time as a key analytical tool. We examine the QSL time for the unitary evolution of two- and three-flavor neutrino states, both in vacuum and in the presence of matter. Two-flavor neutrino oscillations are used as a precursor to their three-flavor counterparts. We further compute the QSL time for neutrino state evolution and entanglement in terms of neutrino survival and oscillation probabilities, which are experimentally measurable quantities in neutrino experiments. A difference in the QSL time between the normal and inverted mass ordering scenarios, for neutrino state evolution as well as for entanglement, under the effect of a $CP$ violation phase is observed. Our results are illustrated using the length scales and energies of ongoing long-baseline accelerator neutrino experiments such as T2K, NOvA, and the upcoming DUNE experiment. Notably, three-flavor neutrino oscillations in constant matter density exhibit faster state evolution across all these neutrino experiments in the normal mass ordering scenario. Additionally, we observe fast entanglement suppression in DUNE assuming a normal mass ordering.

The scattering and absorption rates of light dark matter with electron spin-dependent interactions depend on the target’s spin response. We show how this response is encoded by the target’s dynamical magnetic susceptibility, which can be measured using neutron scattering. We directly use existing neutron scattering data to compute the dark matter scattering rate in a candidate target material, finding close agreement with the previous first-principles calculation at MeV dark matter masses. Complementary experiments and measurements can extend the reach of this technique to other dark matter models and masses, and identify promising target materials for future experiments.

In view of difficulty to reproduce observables in the $D^0-{\overline{D}}^0$ mixing via the operator product expansion, we discuss the Dyson-Schwinger approach to this process. Formulated by the parametrization of quark propagators, SU(3) breaking relevant to charm mixing is evaluated in such a way that properly takes account of dynamical chiral symmetry breaking. The ${\overline{D}}^0\to D^0$ transition is discussed in the vacuum-insertion approximation with locality of the light valence-quark field, represented by the decay constant of $D^0$ meson as well as relevant momentum integrals. It is found that dimensionless mass-difference observable in this approach leads to $|x|=(1.3–2.9)\times {10}^{-3}$, the order of magnitude comparable to the HFLAV data, and thereby offering a certain improvement as a theoretical framework.

To better understand recent predictions on the moat regime of quantum chromodynamics (QCD) matter, this paper extends the previous work within the two-flavor quark-meson (QM) model to the more realistic $2+1$ flavor Polyakov-quark-meson (PQM) model. Mainly, two effects are further taken into account: strange quark and confinement coded through Polyakov loop. Model parameters are chosen to consistently reproduce the pseudocritical temperature from lattice QCD, $T_{\mathrm{C}}\sim 156\mathrm{MeV}$, and the baryon chemical potential at the critical end point (CEP) from functional renormalization group to QCD matter (FRG-QCD), ${\mu }_{\mathrm{B}}(\mathrm{CEP})\sim 635\mathrm{MeV}$. It is found that the basic features of moat regimes for $\sigma$ and $\pi$ mesons remain similar to those from QM model: Moat regimes cover the region where temperature or baryon chemical potential is large; reentrances occur around the critical baryon chemical potential of chiral transition at zero temperature. Thus, the FRG-QCD results can still not be well understood, especially why the extrapolated CEP should be consistent with the boundaries of moat regimes for $\sigma$ and $\pi$ mesons. Nevertheless, some basic features can be understood qualitatively, and it is consistent that the pole energies are increasing functions of momenta in the whole $T-{\mu }_{\mathrm{B}}$ plane. The moat regime and pole energy of $K$ mesons are also studied with the features similar.

We investigate a type of dynamical chiral symmetry breaking ($\mathrm{D}\chi \mathrm{SB}$) for various current quark masses using the interacting instanton liquid model. The type of $\mathrm{D}\chi \mathrm{SB}$ is classified based on the sign of the second derivative of the free energy density with respect to the quark condensate at the origin. We perform numerical simulations of the interacting instanton liquid model with the flavor SU(2) symmetric and ($2+1$)-flavor quarks. We find that the curvature is negative in the SU(2) case. This means the ordinary type of $\mathrm{D}\chi \mathrm{SB}$. In contrast, in the ($2+1$)-flavor case, a positive curvature is observed when the strange quark mass is as small as those of the up and down quarks. This suggests that the anomaly-driven type of $\mathrm{D}\chi \mathrm{SB}$ can occur under the approximate flavor SU(3) symmetry. As the strange quark mass increases, the curvature gradually decreases and becomes negative when the strange quark mass is approximately three times larger than those of the light quarks. This difference can be understood in terms of the ’t Hooft vertex which induces a six-quark interaction in the $N_f=3$ case and does a four-quark interaction in the $N_f=2$ case. Our results might indicate that the ratio between the strange and light quark masses plays a crucial role in understanding the microscopic relationship between $\mathrm{D}\chi \mathrm{SB}$ and the anomaly effect.

Inspired by the states $X(2370)$ and $X(2600)$ reported by the BESIII Collaboration, we systematically investigate the mass spectra of light compact tetraquark states with configurations $ud\overline{u}\overline{d}$, $us\overline{u}\overline{s}$, and $ss\overline{s}\overline{s}$ in the $J^{PC}=0^{-+}$ and $2^{-+}$ channels using the QCD sum rules approach. To effectively describe these tetraquark states, we construct appropriate interpolating tetraquark currents featuring three Lorentz indices while avoiding derivative operators. Through meticulous calculations of correlation functions up to dimension 10 condensates, we extract the mass spectra for both $0^{-+}$ and $2^{-+}$ states by employing the projection operator technique. Our results indicate that the masses of light tetraquarks span 1.5–2.5  GeV for $0^{-+}$ states and 2.4–2.7 GeV for $2^{-+}$ states. Notably, our analysis suggests that the $X(2370)$ state could be interpreted as a $0^{-+}us\overline{u}\overline{s}$ or $ss\overline{s}\overline{s}$ tetraquark state, while the $X(2600)$ state is likely to be a $2^{-+}us\overline{u}\overline{s}$ tetraquark. These intriguing findings warrant further detailed investigation in future studies to better understand the nature of these states.

Mesons’ internal structure and dynamics may be accessed through hard exclusive electroproduction processes such as deeply virtual Compton scattering in both near forward and near backward kinematics. With the help of the Sullivan process, which allows us to use a nucleon target as a quasireal $\pi$ meson emitter, we study backward scattering in the framework of collinear QCD factorization where pion-to-photon transition distribution amplitudes describe the photon content of the $\pi$ meson. We present a model of these transition distribution amplitudes based on the overlap of light-front wave functions primarily developed for generalized parton distributions, using a previously computed pion light-front wave function and deriving a new model for the light-front wave functions of the photon. This leads us to an estimate of the cross sections for JLab energies. We conclude that deeply virtual $ep\to e\gamma Mn$ processes, in backward kinematics, may be experimentally discovered in the near future.

The process of all-vortex nonlinear Compton scattering in an intense and polarized laser field, in which the initial and final electrons and the emitted $\gamma$ photon are all in vortex states, is studied theoretically. We develop a formalism for the process, which allows us to study the exchanges of the orbital angular momentum (OAM) and spin angular momentum among the electron, $\gamma$ photon, and laser. A wave packet of the Bessel-Gaussian type is adopted to describe the initial vortex electron for the purpose of normalization. Both circularly and linearly polarized lasers are examined. Substantial numerical calculations are performed to reveal the physics of the exchanges of the OAM and spin angular momentum. The strong impact of the laser intensity and the opening angle of the initial vortex electron is demonstrated. Our results also suggest possible scenarios for the separation of the emitted $\gamma$ photons with different OAMs, as well as a possible way which could help to distinguish the OAM and spin of the vortex particle by the multipeak structure in the spectrum of the emitted photon.

Based on $e^{+}{e}^{-}$ collision data corresponding to an integrated luminosity of about $4.5{\mathrm{fb}}^{-1}$ collected at center-of-mass energies between 4599.53 and 4698.82 MeV with the BESIII detector, the absolute branching fraction of the Cabibbo-favored decay ${\mathrm{\Lambda }}_c^{+}\to \mathrm{\Lambda }{K}_S^0{K}^{+}$ is measured to be $(3.12\pm 0.46\pm 0.15)\times {10}^{-3}$. Combined with a previous measurement from the BESIII Collaboration, the branching fraction of the decay ${\mathrm{\Lambda }}_c^{+}\to \mathrm{\Lambda }{K}_S^0{K}^{+}$ is calculated to be $(3.07\pm 0.26\pm 0.13)\times {10}^{-3}$. The decay ${\mathrm{\Lambda }}_c^{+}\to {\mathrm{\Xi }}^0{K}_S^0{\pi }^{+}$ is observed for the first time with a statistical significance of $6.6\sigma$, and its branching fraction is determined to be $(3.70\pm 0.60\pm 0.21)\times {10}^{-3}$. In addition, a search for the decay ${\mathrm{\Lambda }}_c^{+}\to {\mathrm{\Sigma }}^0{K}_S^0{K}^{+}$ is performed, and its branching fraction is determined to be $(0.80_{-0.24}^{+0.28}\pm 0.16)\times {10}^{-3}$, corresponding to an upper limit of $1.28\times {10}^{-3}$ at a 90% confidence level. These measurements provide new information that can be used to distinguish between theoretical models.

We introduce a novel approach that utilizes neutrino events from the off-axis near detector to investigate the beam profile in long-baseline neutrino experiments. Understanding the dynamics of the neutrino beam is crucial for improving the precision of neutrino oscillation measurements. We demonstrate that certain observables related to the azimuthal angle of the neutrino direction are useful for determining the average neutrino production point from experimental data, providing a valuable cross-check against Monte Carlo simulations. Additionally, these observables can help identify potential alignment issues between the detector and the decay volume. In future neutrino experiments with significantly higher statistics, these observables will become essential to ensure the accuracy and stability of the beam profile.

Lenzi and Sopuerta developed a new method to construct master functions for the perturbation of vacuum black holes. We extend this method to black holes coupled with electromagnetic field and cosmological constant by allowing the master functions to be linear combinations of the metric and electromagnetic-potential perturbations, as well as their first-order derivatives. Requiring these master functions satisfy wave equations with yet-to-be-determined effective potentials, we reduce the linearized Einstein-Maxwell system to a set of algebraic-differential constraints. Solving these constraints reveals four master function branches in each parity sector: two standard branches, which coincide with the Zerilli-Moncrief formalism, and two Darboux branches, characterized by their effective potentials. Within each parity sector, a Darboux transformation exists which connects the standard and Darboux branches, preserving the quasinormal mode spectrum and confirming their physical equivalence.

Black hole spacetimes that exhibit integrable singularities have gained considerable interest as alternatives to both regular and singular black holes. Unlike most known regular black hole solutions, these models evade the formation of an inner horizon, thereby circumventing the well-known instability issues associated with such structures. Moreover, it has been suggested that the finite tidal forces near integrable singularities may allow for a traversable extension beyond them. In this work, we present a set of arguments—both theoretical, concerning test-field perturbations and the accumulation of matter at the singularity, and practical, related to the behavior of physical probes and extended objects—with the aim of assessing the validity of the proposed integrability condition, and the feasibility of traversing such singularities. Our analysis highlights key subtleties that challenge the viability of said extensions as alternatives to regular black holes, and underscores the need for a more rigorous investigation of their physical implications.

Precision measurements of the gravitational wave signal from compact binary inspirals allow us to constrain the internal structure of those objects via physical parameters such as the tidal Love numbers. In scalar-tensor theories, one typically finds new types of Love numbers that are usually not considered or simply absent in general relativity, which further allows us to constrain deviations from general relativity. Building upon previous results, we present the linear perturbation equations necessary to calculate static and even-parity tidal Love numbers in Horndeski theories, the most general scalar-tensor theories with second-order field equations of motion. We further focus on the quadrupolar Love numbers and demonstrate how these can be extracted from the asymptotic expansion of the perturbation fields. We find that there is a potential ambiguity in extracting the Love numbers in this way, which we resolve by performing supplementary calculations in the effective field theory framework. We show that, in the case of scalar-tensor theories, the tidal Love numbers are not directly given by the $1/r^3$ term in the asymptotic expansion of the perturbation fields, as there is an additional contribution to this term independent of the Love numbers. We calculate such a contribution for a minimally coupled scalar field and also for the Damour-Esposito-Farèse model. For the latter, we find that the Love numbers can differ by $\mathcal{O}(1\sim 10)\%$, if this additional contribution is not taken into account.

Gravitational wave (GW) detectors, such as LIGO, Virgo, and KAGRA, detect faint signals from distant astrophysical events. However, their high sensitivity also makes them susceptible to background noise, which can obscure these signals. This noise often includes transient artifacts called “glitches” that can mimic genuine astrophysical signals or mask their true characteristics. In this study, we present DeepExtractor, a deep learning framework that is designed to reconstruct signals and glitches with power exceeding interferometer noise, regardless of their source. We design DeepExtractor to model the inherent noise distribution of GW detectors, following conventional assumptions that the noise is Gaussian and stationary over short timescales. It operates by predicting and subtracting the noise component of the data, retaining only the clean reconstruction of the signal or glitch. We focus on applications related to glitches and validate DeepExtractor’s effectiveness through three experiments: (1) reconstructing simulated glitches injected into simulated detector noise, (2) comparing its performance with the state-of-the-art BayesWave algorithm, and (3) analyzing real data from the Gravity Spy dataset to demonstrate effective glitch subtraction from LIGO strain data. We further demonstrate its potential by reconstructing three real GW events from LIGO’s third observing run, without being trained on GW waveforms. Our proposed model achieves a median mismatch of only 0.9% for simulated glitches, outperforming several deep learning baselines. Additionally, DeepExtractor surpasses BayesWave in glitch recovery, offering a dramatic computational speedup by reconstructing one glitch sample in approximately 0.1 s on a CPU, compared to BayesWave’s processing time of approximately one hour per glitch.

We investigate an exact two-parameter family of plane symmetric solutions admitting a hypersurface-orthogonal Killing vector in general relativity with a perfect fluid obeying a linear equation of state $p=\chi \rho$ in $n(\ge 4)$ dimensions obtained by Gamboa in 2012. The Gamboa solution is identical to the topological Schwarzschild–Tangherlini–(anti–)de Sitter $\mathrm{\Lambda }$-vacuum solution for $\chi =-1$ and admits a nondegenerate Killing horizon only for $\chi =-1$ and $\chi \in [-1/3,0)$. We identify all possible regular attachments of two Gamboa solutions for $\chi \in [-1/3,0)$ at the Killing horizon without a lightlike thin shell, where $\chi$ may have different values on each side of the horizon. We also present the maximal extension of the static and asymptotically topological Schwarzschild-Tangherlini Gamboa solution, realized only for $\chi \in (-(n-3)/(3n-5),0)$, under the assumption that the value of $\chi$ is unchanged in the extended dynamical region beyond the horizon. The maximally extended spacetime describes either (i) a globally regular black bounce whose Killing horizon coincides with a bounce null hypersurface or (ii) a black hole with a spacelike curvature singularity inside the horizon. The matter field inside the horizon is not a perfect fluid but rather an anisotropic fluid that can be interpreted as a spacelike (tachyonic) perfect fluid. A fine-tuning of the parameters is unnecessary for the black bounce, but the null energy condition is violated everywhere except on the horizon. In the black-bounce (black-hole) case, the metric in the regular coordinate system is $C^{\infty }$ only for $\chi =-1/(1+2N)$ with odd (even) $N$ satisfying $N>(n-1)/(n-3)$, and if one of the parameters in the extended region is fine-tuned.

Accurate and efficient modeling of the Laser Interferometer Space Antenna (LISA) response is crucial for gravitational-wave (GW) data analysis. A key computational challenge lies in evaluating time-delay interferometry (TDI) variables, which require projecting GW polarizations onto the LISA arms at different retarded times. Without approximations, the full LISA response is computationally expensive, and traditional approaches, such as the long-wavelength approximation, accelerate the response calculation at the cost of reducing accuracy at high frequencies. In this work, we introduce a novel hybrid time-domain response for LISA that balances computational efficiency and accuracy across the binary’s evolution. Our method is applicable to massive black hole binaries and implements a fast low-frequency approximation during the early inspiral—where most of these binaries spend most of the time in the sensitive frequency band of LISA—while reserving the computationally intensive full-response calculations for the late inspiral, merger, and ringdown phases. The low-frequency approximation (LFA) is based on Taylor expanding the response quantities around a chosen evaluation time such that time delays correspond to central finite differences. Our hybrid approach supports CPU and GPU implementations, TDI generations 1.5 and 2.0, and flexible time-delay complexity, and has the potential to accelerate parts of the global fit and reduce energy consumption. We also test our LFA and hybrid responses on eccentric binaries, and we perform parameter estimation for a “golden” binary. Additionally, we assess the efficacy of our low-frequency response for “deep alerts” by performing inspiral-only Bayesian inference.

Coupled dark sector models have gained significant attention, motivated by recent advances in cosmology and the pressing need to address unresolved puzzles. In this work, we study coupled scalar dark sector models inspired by ultraviolet-complete frameworks such as supergravity and string theory. These models involve scalar couplings arising either from their kinetic terms, through a nontrivial field space metric, or from their scalar potential. We demonstrate how these couplings can be elegantly formulated in terms of an interacting vector, a standard tool in coupled dark sector studies, and analyse their distinct cosmological effects using a dynamical systems approach. Using this framework, we further investigate an axio-dilaton system recently explored in the literature, where the dilaton also couples to baryons. Intriguingly, we show that certain kinetic and potential interactions may mimic one another or even cancel out, making them observationally indistinguishable. If such a distinction becomes possible through observational constraints, it could provide valuable insights into the underlying field space metric and its connection to fundamental physics.

The flavor composition of TeV—PeV astrophysical neutrinos, i.e., the proportion of neutrinos of different flavors in their flux, is a versatile probe of high-energy astrophysics and fundamental physics. Because flavor identification is challenging and the number of detected high-energy astrophysical neutrinos is limited, so far measurements of the flavor composition have represented an average over the range of observed neutrino energies. Yet, this washes out the potential existence of changes in the flavor composition with energy and weakens our sensitivity to the many models that posit them. For the first time, we measure the energy dependence of the flavor composition, looking for a transition from low to high energies. Our present-day measurements, based on the 7.5-year public sample of IceCube high-energy starting events (HESE), find no evidence of a flavor transition. The observation of HESE and through-going muons jointly by next-generation neutrino telescopes Baikal-GVD, IceCube-Gen2, KM3NeT, P-ONE, TAMBO, and TRIDENT may identify a flavor transition around 200 TeV by 2030. By 2040, we could infer the flavor composition with which neutrinos are produced with enough precision to establish the transition from neutrino production via the full pion decay chain at low energies to muon-damped pion decay at high energies.

We construct a set of unified equations of state based on the quark mean-field (QMF) model, calibrated to different values of nuclear symmetry energy slope at the saturation density ($L_0$), with the aim of exploring both the static properties and dynamical behavior of neutron stars (NSs), and building a coherent picture of their internal structure. We assess the performance of these QMF models in describing the mass-radius relation, the cooling evolution of isolated NSs and x-ray transients, and the instabilities (e.g., the r mode). In comparison to relativistic mean-field (RMF) models formulated at the hadronic level, the QMF model predicts heavier nuclear clusters and larger Wigner-Seitz cell sizes in the NS crust, while the density of the free neutron gas remains largely similar between the two approaches. For the cooling of isolated NSs, the thermal evolution is found to be insensitive to both the many-body model and the symmetry energy slope in the absence of the direct Urca (dUrca) process. However, when rapid cooling via the dUrca process is allowed, in the case of large $L_0$ values (e.g., $L_0\gtrsim 80\mathrm{MeV}$) in our study, the QMF model predicts a longer thermal relaxation time. Both the QMF and RMF models can reproduce cooling curves consistent with observations of x-ray transients (e.g., KS 1731-260) during their crustal cooling phase, although stellar parameters show slight variations depending on the model and symmetry energy slope. Within our unified framework, a larger $L_0$ value generally results in a wider instability window, while increasing the stellar mass tends to suppress the instability window. We also provide simple power-law parametrizations that quantify the dependence of bulk and shear viscosities on the symmetry energy slope for nuclear matter at saturation density.