We present the ground-state energy spectra of dibaryons composed of single-flavor quarks, specifically systems with strangeness $\mathcal{S}=-6$ and charm $\mathcal{C}=6$. Our lattice QCD study is based on $N_f=2+1+1$ MILC ensembles with highly improved staggered quark sea quarks, spanning four lattice spacings and two spatial volumes. We employ valence quark propagators realized using a relativistic overlap action, evaluate correlation matrices with carefully designed operator bases, and extract reliable ground-state energy estimates in the $S=0$ and $S=2$ spin channels. We explore their binding characteristics and interaction dynamics by examining the energy separation between the dibaryon states and the corresponding two-baryon thresholds. These results contribute to a deeper understanding of single-flavor dibaryon states as a function of the quark masses. In the $S=0$ channel, the ${\mathrm{\Omega }}_{ccc}\text{−}{\mathrm{\Omega }}_{ccc}$ system exhibits a clear signal of a bound state, while the $\mathrm{\Omega }\text{−}\mathrm{\Omega }$ system lies very close to the threshold, making it difficult to draw definitive conclusions. For $S=2$, both systems are found to be unbound.

Motivated by the large non-$D\overline{D}$ branching fraction of ${\psi }_1(3770)$, we investigate the light meson decays of the $D$-wave charmonia in the present work with the meson loop mechanism. With the parameter range determined by ${\psi }_1(3770)\to \varphi \eta$, our estimations of the branching fractions of the light meson decays of ${\psi }_1(3770)$ are consistent with the estimations in the literature. As for ${\psi }_2(3823)$, the partial widths of $K^{*}{\overline{K}}^{*}$ channel is estimated to be around 200 keV, which is the predominant light meson decay channel of ${\psi }_2(3823)$. Our estimations also indicate that $K^{(*)}{\overline{K}}^{(*)}$ and $\rho \pi$ are the dominant light meson decay modes of ${\psi }_3(3842)$, while ${\eta }_{c2}(3822)$ dominantly decays into $\rho \rho$, $K^{*}{\overline{K}}^{*}$, $\omega \omega$, and $\varphi \varphi$.

The photoproduction of doubly charmed tetraquark $T_{cc}$ is predicted through the resolved channel $\gamma +g\to ⟨cc⟩[n]+\overline{c}+\overline{c}\to T_{cc}+\overline{c}+\overline{c}$ at ILC and CLIC. At $e^{+}{e}^{-}$ colliders, the initial photons $\gamma$ can be produced from two primary sources, well-delineated within the Weizäcker Williams approximation (WWA) and the laser backscattering (LBS). And the initial gluon can be emitted from the photon. The spin and color quantum number [$n$] of the intermediate diquark configuration can be $⟨cc⟩[{{}^{3}S}_1{]}_{\overline{3}}$. Then its nonperturbative hadronization to $T_{cc}$ was discussed in the phenomenological potential models. Finally, the differential distributions and theoretical uncertainty of the doubly charmed tetraquark $T_{cc}$ were analyzed. As the collision energy increases, the contribution of the resolved photon channel will become increasingly significant, and it may even dominate the production of $T_{cc}$ with the laser backscattering spectrum. The conclusion is that it is promising to observe $T_{cc}$ via the resolved channel of photoproduction both at the ILC and CLIC, and the results have a strong dependence on the mass of constituent charm quark $m_c$ and the potential model.

The neutrino energy reconstruction is crucial for reducing systematic uncertainties in neutrino oscillation experiments and improving cross section measurements. Kaon-decays-at-rest (KDAR) neutrinos provide a unique opportunity to probe neutrino-nucleus interactions at low energies with a precisely known energy of 235.5 MeV. This work presents Monte Carlo predictions of missing energy due to nuclear effects in the KDAR ${\nu }_{\mu }$ charged-current scattering on the carbon nucleus for the J-PARC sterile neutrino search at the J-PARC Spallation Neutron Source. The predictions from genie, nuwro, and gibuu show a significant impact of nuclear and final-state interaction (FSI) models, as well as nucleon removal energy, on missing energy reconstruction. Tuning the hA FSI model improves the predictions from genie. It is also observed that the nucleon elastic component of FSI leads to better predictions in nuwro compared to genie. nuwro shows the best agreement with data among the generators considered; however, the observed discrepancies with data across all generators highlight the limitations of current theoretical descriptions in the low-energy regime and the need for improvements in Monte Carlo modeling.

Current ton-scale dark matter direct detection experiments have reached an important milestone with the detection of solar neutrinos. In this paper, we show that these data can be used to determine a critical parameter of the Standard Model in particle physics, across an energy regime that has never been probed before. In particular, we show that the value of the weak mixing angle (${\theta }_W$) which relates the mass of the $W$ and $Z$ bosons can be derived from (1) the recent measurements of coherent neutrino-nucleus scattering by PandaX-4T and XENONnT in the sub-GeV energy range—a regime which is usually only probed by low energy neutrino experiments—and from (2) XENONnT electron recoil data through neutrino-electron scattering at energy scale $\simeq 0.1\mathrm{MeV}$, corresponding to a momentum transfer region over an order of magnitude smaller than that explored by atomic parity violation experiments. Now that an indicative measurement of the weak mixing angle exists at these lowest energy frontier, the challenge for the next generation of such experiments will be to provide a more precise measurement in the keV–MeV energy range.

$\text{DMRadio-}{\mathrm{m}}^3$ is an experimental search for dark matter axions. It uses a solenoidal dc magnetic field to convert an axion dark-matter signal to an ac electromagnetic response in a coaxial copper pickup. The current induced by this axion signal is measured by dc SQUIDs. $\text{DMRadio-}{\mathrm{m}}^3$ is designed to be sensitive to Kim-Shifman-Vainshtein-Zakharov (KSVZ) and Dine-Fischler-Srednicki-Zhitnisky (DFSZ) QCD axion models in the 10–200 MHz ($41\mathrm{neV}/c^2–0.83\mathrm{\mu }\mathrm{eV}/c^2$) range, and to axions with $g_{a\gamma \gamma }=g_{a\gamma \gamma ,\mathrm{DFSZ}}(30\mathrm{MHz})=1.87\times {10}^{-17}{\mathrm{GeV}}^{-1}$ over 5–30 MHz as an extended goal. In this work, we present the electromagnetic modeling of the response of the experiment to an axion signal over the full frequency range of $\text{DMRadio-}{\mathrm{m}}^3$, which extends from the low-frequency, lumped-element limit to a regime where the axion Compton wavelength is only a factor of 2 larger than the detector size. With these results, we determine the live time and sensitivity of the experiment. The primary science goal of sensitivity to DFSZ axions across 30–200 MHz can be achieved with a $3\sigma$ live scan time of 2.9 years.

We perform a rigorous analysis of the $\pi K$ scattering at an unphysical pion mass 391 MeV using the Roy-Steiner equations, which satisfy unitarity, analyticity, and crossing symmetry, for the first time. Stable solutions of the Roy-Steiner equations with different quantum numbers of isospin and angular momentum are obtained in the elastic energy region, by taking inputs from the $\pi K$ lattice data in the inelastic region, the lattice data from the crossed $\pi \pi \to K\overline{K}$ channels, the masses of $f_0(500)$ and $K^{*}$ at the same pion mass from previous study, and the Regge model. Predictions on the elastic $\pi K$ scattering phase shifts and the $K_0^{*}(700)$ pole content are made. Contrary to the virtual pole scenario obtained using the $K$-matrix method in the literature, we find that lightest strange scalar meson $K_0^{*}(700)$ remains a broad resonance at $m_{\pi }=391\mathrm{MeV}$. The cross-channel dynamics is found to play a crucial role in deriving the proper pole position.

Based on the studies of pseudoentropy in de Sitter, there have been recent proposals for a timelike entanglement in AdS/CFT. In this work, we explore this proposal in the context of a holographic CFT undergoing a global quench. We study various cases in which the timelike intervals are anchored at various boundary times, sometimes straddling the infalling shell. The early and late time behaviors reproduce the known results coming from the pure AdS and the black hole geometry dual to the thermal CFT state respectively. However when the infalling shock straddles the timelike interval, the dynamics drastically differs from how the entanglement entropy evolves.

Newtonian and post-Newtonian (PN) calculations suggest that each spherical harmonic mode of the gravitational waveforms (radiation) emitted by eccentric binaries can be further decomposed into several eccentricity-induced modes (indexed by $j=1$ to $j=\infty$), referred to as eccentric harmonics. These harmonics exhibit monotonically time-varying amplitudes and instantaneous frequencies, unlike the full eccentric spherical harmonic modes. However, computing or extracting these harmonics is not straightforward in current numerical relativity simulations and eccentric waveform models. To address this, Patterson et al. [Phys. Rev. D 111, 044073 (2025)] have developed a framework to extract the eccentric harmonics directly from effective-one-body formalism waveforms. In this paper, we build on the ideas presented in Patterson et al. and propose a data-driven framework, utilizing singular-value decomposition, that incorporates additional features based on PN intuition to ensure monotonicity in the extracted harmonics. We further demonstrate that the phase (frequency) of these harmonics is simply $j{\varphi }_{\lambda }+{\varphi }_{\mathrm{ecc}}$ ($j{f}_{\lambda }+f_{\mathrm{ecc}}$), where ${\varphi }_{\lambda }$ ($f_{\lambda }$) is related to the secular orbital phase (frequency) and ${\varphi }_{\mathrm{ecc}}$ ($f_{\mathrm{ecc}}$) is an additional phase (frequency) that only depends on the eccentricity. We also provide simple analytical fits to obtain the harmonics as a function of the mean anomaly. These relations may prove useful in constructing faithful models (such as [gwharmone: First data-driven surrogate for eccentric harmonics in binary black hole merger waveforms (to be published).]) that can be employed in cheap and efficient searches and parameter estimation of eccentric mergers. Our framework is modular and can be extended for any other eccentric waveform models or simulation frameworks. The framework is available through the gwminer package.

A black hole illuminated by a background light source is observed as a black hole shadow. For a black hole formed by gravitational collapse of a transmissive object, redshift of light due to the spacetime dynamics is expected to play a crucial role in the shadow formation. In this paper, we investigate the redshift of light caused by the spacetime dynamics. First, we consider a spherical shell model. We see that the collapse of the shell typically leads to the redshift of light, while blueshift can be also observed in some cases. This result suggests that a shadow image is generally formed in the late stage of the gravitational collapse of a transmissive object. Second, we propose a covariant formula for the redshift of light in a general, dynamical, and spherically symmetric spacetime. This formula relates the redshift to the energy-momentum tensor of the background spacetime and provides its intuitive interpretation with a Newtonian analogy. The redshift effect analyzed in this work is regarded as the integrated Sachs-Wolfe effect or the Rees-Sciama effect in gravitational collapse.

Studying spinning magnetized particles in strong gravitational and electromagnetic fields is crucial for understanding astrophysical processes near black holes, particularly in the scenarios of millisecond pulsars orbiting supermassive or intermediate-mass black holes. In this work, we analyze the circular motion and collisions of such particles in the close environment of a magnetized Kerr black hole, considering both spin-curvature and magnetic dipole interactions. Using the Mathisson-Papapetrou-Dixon (MPD) equations, we derive the effective potential governing the circular motion of spinning magnetized particles and investigate the innermost stable circular orbit (ISCO) under the influence of black hole spin, external magnetic fields, and intrinsic particle spin and magnetic dipole moment. The results reveal how the interaction of the magnetic dipole moment with the external field and spin-curvature interactions significantly alter stable orbits, leading to modifications in accretion dynamics. Furthermore, we explore the center-of-mass energy of such high-energy particle collisions, demonstrating that spin and magnetic interactions can amplify collision energies beyond the standard Bañados-Silk-West (BSW) process, with implications for the production of ultrahigh-energy cosmic rays and the formation of jets in active galactic nuclei and low-luminosity galaxies. Our findings may provide theoretical predictions that can be tested using observations of compact objects in strong magnetic fields, such as pulsars near supermassive black holes.

The most general bound binary black hole system has an eccentric orbit and precessing spins. The detection of such a system with significant eccentricity close to the merger would be a clear signature of dynamical formation. In order to study such systems, it is important to be able to evolve their spins and eccentricity from the larger separations at which the binary formed to the smaller separations at which it is detected, or vice versa. Knowledge of the precessional evolution of the binary’s orbital angular momentum can also be used to twist up aligned-spin eccentric waveform models to create a spin-precessing eccentric waveform model. In this paper, we present a new publicly available code to evolve eccentric, precessing binary black holes using orbit-averaged post-Newtonian (PN) equations from the literature. The spin-precession dynamics is 2PN accurate, i.e., with the leading spin-orbit and spin-spin corrections. The evolution of orbital parameters (orbital frequency, eccentricity, and periastron precession), which follow the quasi-Keplerian parametrization, is 3PN accurate in the point particle terms and includes the leading order spin-orbit and spin-spin effects. All the spin-spin terms include the quadrupole-monopole interaction. The eccentricity enhancement functions in the fluxes use the high-accuracy hyperasymptotic expansions from Loutrel and Yunes [Classical Quantum Gravity 34, 044003 (2017)]. We discuss various features of the code and study the evolution of the orbital and spin-precession parameters of eccentric, precessing binary black holes. In particular, we study the dependence of the spin morphologies on eccentricity, where we find that the transition point from one spin morphology to another can depend nonmonotonically on eccentricity, and the fraction of binaries in a given morphology at a given point in the evolution of a population depends on the instantaneous eccentricity.

We study the possibility that parametric resonant excitation of photons in an ultralight dark matter halo could generate the required flux of Lyman-Werner photons to allow the direct collapse formation of supermassive black hole seeds.

We study the Kaiser formula for biased tracers in massive neutrino cosmologies by comparing its predictions with a large set of N-body simulations. In particular, we examine the ambiguity in the definition of the peculiar velocity contribution at linear level, whether it should be expressed in terms of the total matter velocity field or only the cold-matter component, comprised of cold dark matter and baryons. We revisit and extend previous qualitative studies on the topic with larger statistics and including a full fit of halo power spectrum and halo-matter cross-power spectrum measurements. We find clear evidence that the clustering of halos in redshift space is correctly described assuming that halo velocity is tracing the velocity field of cold-matter. The opposite assumption provides a worse fit to the simulated data and can lead to a spurious running of nuisance parameters in the perturbative galaxy power spectrum model.

Gravitational lensing magnification is maximal around caustics. At these source locations, an incoming wave from a point source would formally experience an infinite amplification in the high-frequency or geometric optics limit. This divergence reflects the breakdown of the mathematical formalism, which is regularized by either the finite size of the source or its wavelength. We explore diffraction around caustics and their implications for the distortion of waveforms from point sources, focusing on three types of caustics: point singularities, folds, and cusps. We derive analytical results for the amplitude and phase of the diffracted waves and compare those against the stationary phase approximation. We then study the observational signatures and detectability of these distortions on gravitational waves. We find that the lensing distortions could be detectable but that the stationary phase approximation is still a good description of the system even close to the caustic, when the repeated gravitational wave chirps interfere with each other. We also quantify the possibility of distinguishing lensed signals from different caustics by performing Bayesian parameter estimation on simulated signals. Our results demonstrate that the universal distortions due to diffraction around caustics could be used to single out a gravitational wave event as lensed.

The recent announcement of evidence for a stochastic background of gravitational waves (GWB) in pulsar timing array (PTA) data has piqued interest across the scientific community. A combined analysis of all currently available data holds the promise of confirming the announced evidence as a solid detection of a GWB. However, the complexity of individual pulsar noise models and the variety of modeling tools used for different types of pulsars present significant challenges for a truly unified analysis. In this work we propose a novel approach to the analysis of PTA data: first a posterior distribution over Fourier modes is produced for each pulsar individually. Then, in a global analysis of all pulsars, these posterior distributions can be reused for a GWB search, which retains all information regarding the signals of interest without the added complexity of the underlying noise models or implementation differences. This approach facilitates combining radio and gamma-ray pulsar data, while reducing the complexity of the model and of its implementations when carrying out a GWB search with PTA data.

We consider a spinning primordial black hole (PBH) described by the Kerr metric in Kerr-Schild polar coordinates. We derive an analytical expression for the four-vector gravitational potential in the underlying Hermitian Dirac Hamiltonian using these coordinates. This gravitational potential introduces an axial vector term in the Dirac equation in curved spacetime. We find that the magnitudes of the temporal and spatial components of the four-vector gravitational potential are significantly affected by the angle of the position vector of the spinor with respect to the spin axis of the PBH, its radial distance from the PBH, and the strength of the specific angular momentum of the PBH. These potentials modify the effective mass matrix of the neutrino-antineutrino system and significantly affect the transition probabilities during the flavor oscillation of the neutrino-antineutrino system. We then use the transition probability to investigate the quantum speed limit time bound ratio for the two-flavor oscillation of the neutrino-antineutrino system in curved spacetime. This helps us estimate how quickly the initial neutrino flavor state evolves over time under the influence of the gravitational field. Finally, we discuss quantum correlations such as entanglement entropy during the two-flavor oscillation of the neutrino-antineutrino system near a spinning PBH.

Building upon the success of optimal transport metrics defined for single collinear jets, we develop a multiscale framework that models entire collider events as distributions on the manifold of their constituent jets, which are themselves distributions on the ground space of the calorimeter. This hierarchical structure of optimal transport effectively captures relevant physics at different scales. We demonstrate the versatility of our method in two event classification tasks, which respectively emphasize intrajet substructure and interjet spatial correlations. Our results highlight the importance of a nested structure of manifolds in the treatment of full collider events, broadening the applicability of optimal transport methods in collider analyses.

Metastable cosmic strings (MSCSs) are among the best-fitting explanations of the 2023 pulsar timing array (PTA) signal for gravitational waves at nanohertz frequencies. We propose the novel possibility that a network of MSCSs generating this signal originates from the multistep spontaneous breaking of a gauged flavor symmetry. As a specific example, we construct a model of $SU(2)$ flavor symmetry in the context of $SU(5)$ grand unification, where the $SU(2)$ acts exclusively on the first two generations of the matter 10-plet, such that it is “right for leptons” and allows for large lepton mixing. The model explains the mass hierarchies of the Standard Model fermions, and predicts the string scale of the MSCSs in a range compatible with the 2023 PTA signal. Cosmic inflation is associated with the latter step of (two-step) family symmetry breaking, and the phase transition ending inflation generates the cosmic string network.