Inspired by the experimental discoveries of $X(3872)$ ($c\overline{q}q\overline{c}$) and $T_{cc}$ ($c\overline{q}c\overline{q}$), we systematically study their orbitally excited strange partners, i.e., the $K{\overline{K}}_1$ ($q\overline{s}s\overline{q}$) system, which may be related to the recently observed ${\eta }_1(1855)$, and the $K{K}_1$ ($q\overline{s}q\overline{s}$) system. Within the framework of an accurate few-body calculation method, we employ the chiral quark model to investigate both the molecular and diquark structures of these two multiquark systems in addition to channel coupling effects. Our results show that the $K{\overline{K}}_1$ system remains a scattering state, although we have considered two different sets of parameters in our calculations to avoid the influence of parameters. On the other hand, due to the presence of a good-diquark structure in the $K{K}_1$ system, we obtain a very shallow bound state in the coupled-channel calculation, where the one-gluon, the $\eta$-meson, $f_0$-meson, and $\sigma$-meson exchanges play crucial roles. The interquark distance and component analysis also suggest that it is a loosely bound molecular state.

We study the three-body decays ${\mathrm{\Lambda }}_b\to D^{+}{D}^{-}\mathrm{\Lambda },D^0{D}_s^{-}p,D_s^{+}{D}_s^{-}\mathrm{\Lambda }$, considering both internal and external emission mechanisms that produce various meson-baryon final states. Using a unitarized coupled-channel approach based on the local hidden gauge formalism, we analyze final state interactions in the exotic anticharm systems with strangeness $S=-1$ and $S=-2$. Significant threshold enhancements appear in both pseudoscalar and vector meson-baryon channels, indicating strong final state interactions and the possible formation of molecular exotic states below threshold. These features remain stable under variations of model parameters. Our results provide valuable insights into heavy hadron decay dynamics and offer theoretical guidance for future experimental searches of open-charm strange exotic hadrons. These results take into account the effects of the $D^{+}\mathrm{\Lambda }$ and $D^{+}{D}^{-}$ interactions, three-body rescattering, possible triangle singularities, parameter uncertainties, and large $N_c$ behavior, making the predictions very reliable.

The standard description of the nucleon in the nonrelativistic quark model is an $1S,L=0$ state without orbital motion. Yet, there are several indications from phenomenology that an admixture of states with nonzero orbital motion maybe substantial. In this paper we focus on the “second shell” of the nucleon excitations (D-shell), for which we give a modern description of the wave functions. We follow it by investigating what we call a “maximal mixing” scenario, assuming a hypothetical long-range tensor force. We give the explicit wave functions for all states, before and after mixing, and reassess many predictions such as the magnetic moments, the standard and transitional form-factors from the nucleon to $N^{*}$. Unexpectedly, in this scenario we can reproduce the long-puzzling features of the Roper resonance $N^{*}(1440)$. But even in this extreme case, the admixture of the $1D,L=2$ state to a nucleon remains significantly smaller than expected from phenomenology.

We study the sensitivity to longitudinal vector boson scattering at a 27-, 50-, and 100-TeV pp collider using events containing two leptonically decaying same-electric-charge $W$ bosons produced in association with two jets. The baseline FCC-hh detector parametrization within the Delphes framework is used under the assumption of fully efficient pileup mitigation. A tightly constrained phase space with a dijet mass greater than 2 TeV is considered in order to suppress the impact of potential instrumental backgrounds. Based on this setup, the expected sensitivity to the production of longitudinally polarized same-sign $W$ boson pairs is evaluated. Additionally, expected limits are set on doubly charged Higgs bosons produced via vector boson fusion processes and decaying to same-sign $W$ boson pairs.

We study the Ryu-Takayanagi (RT) surfaces associated with timelike subregions in static spacetimes with a horizon. It is possible to find the analytical continuation of the RT surfaces that can extend into the horizon, allowing us to probe the interior of the black hole. The horizon typically divides the RT surface into two distinct parts. We demonstrate that the area of the surface inside the horizon can be reconstructed from the contributions of the surfaces outside the horizon, along with additional RT surfaces for spacelike subregions that are causally related to the timelike subregions. This result provides a concrete realization of black hole complementarity at the level of classical metric, where the spacetime in the black hole interior can be reconstructed from the degrees of freedom outside the horizon.

In this work we study timelike circular orbits and photon orbits at the throat of stationary and axisymmetric wormholes. We assume a global radial coordinate $l$ connecting both sides, with twice differentiable metric components and vanishing first derivatives at the throat. With regard to the specific angular momentum $\ell$ of a test particle, we derive expressions for the boundaries of a spectrum of bound circular orbits. We further express these boundaries in terms of physical properties of the spacetime. With regard to the parameter space behavior, we found a phase transition occurring for wormholes with an ergoregion. Furthermore, the presented expressions could give constraints on wormhole properties, as they hint to possible instabilities, especially for fast rotating wormholes and wormholes with an ergoregion.

The Axion Dark Matter eXperiment is sensitive to narrow axion flows, given axions comprise a fraction of the dark matter with a non-negligible local density. Detecting these low-velocity dispersion flows requires a high spectral resolution and careful attention to the expected signal modulation due to Earth’s motion. We report an exclusion on the local axion dark matter density in narrow flows of ${\rho }_a\gtrsim 0.03\mathrm{GeV}/{\mathrm{cm}}^3$ and ${\rho }_a\gtrsim 0.004\mathrm{GeV}/{\mathrm{cm}}^3$ for Dine-Fischler-Srednicki-Zhitnitski and Kim-Shifman-Vainshtein-Zakharov axion-photon couplings, respectively, over the mass range $3.3-4.2\mathrm{\mu }\mathrm{eV}$. Measurements were made at selected resolving powers to allow for a range of possible velocity dispersions.

We investigate the asymptotic symmetries of quantum electrodynamics in three dimensions, demonstrating that their actions on asymptotic states are trivial under the assumption of confinement.

Efforts are underway to accurately model extreme-mass-ratio inspirals for binaries with a spinning (Kerr) primary. At lowest order the adiabatic evolution depends on the radiation fluxes. Fluxes and other self-force quantities can be expanded analytically in post-Newtonian (PN) series allowing the early evolutionary phase to be understood. When it comes to more complicated background geodesic orbits, it proves useful to use the scalar field model problem to guide development and testing of techniques. In this paper, we present analytical expressions for the scalar fluxes from a scalar point charge in inclined-spherical orbit about a Kerr black hole up to 12PN relative order, with expressions that are exact in terms of the inclination parameter $x$ and black hole spin $a$. The expressions are constructed using the Mano, Suzuki, and Takasugi method of solving the scalar wave equation in a Kerr background. We compare the numerical evaluation of these flux expressions to full numerical ($s=0$) teukolsky code results, examining their degree of utility as the strong-field region is approached.

A magnetic field enables the interconversion of photons and gravitons, yet the process is usually analyzed only at the level of classical wave equations. We revisit photon-graviton conversion in a quantum field theoretic framework, allowing us to track the evolution of arbitrary quantum states. Treating the photons as squeezed coherent states and the gravitons as the squeezed vacuum expected for primordial gravitational waves, we derive analytic expressions for the conversion probability and show that it can be significantly enhanced compared to the conventional estimate. We further demonstrate that the conversion both swaps preexisting entanglement and generates genuinely new entanglement between the electromagnetic and gravitational sectors, which is impossible in any classical description. Detecting such nonclassical correlations would constitute compelling evidence for the quantization of gravity and offers a novel pathway toward graviton detection.

We demonstrate that Type Ia supernovae (SNe Ia) observations impose the critical constraint for resolving the Hubble tension through late-time expansion modifications. Applying the Fisher-bias optimization framework to cosmic chronometers (CCs), baryon acoustic oscillations (BAOs) from Dark Energy Spectroscopic Instrument (DESI) Data Release 2, Planck cosmic microwave background, and $\mathrm{Pantheon}+\text{data}$, we find that (i) deformations in $H(z\lesssim 3)$ [via $w(z)$ reconstruction] can reconcile tensions between CC, Planck, DESI BAO, and SH0ES measurements while maintaining or improving fit quality [$\mathrm{\Delta }{\chi }^2<0$ relative to $\mathrm{\Lambda }$ cold dark matter ($\mathrm{\Lambda }\mathrm{CDM}$)]. (ii) In the neighborhood of the Planck best-fit $\mathrm{\Lambda }\mathrm{CDM}$ model, no cosmologically viable solutions targeting $H_0\gtrsim 69$ satisfy SNe Ia constraints. Markov chain Monte Carlo validation confirms the maximum achievable $H_0=69.15\pm 0.32$ (${\chi }_{\mathrm{BF}}^2\approx {\chi }_{\mathrm{\Lambda }\mathrm{CDM}}^2$) across all data combinations, indicating that the conflict between late-time $w(z)$ modifications and SNe Ia observations prevents complete resolution of the Hubble tension.

We study a dark energy model composed of a bare negative cosmological constant and a single ultralight axion, motivated by the string axiverse. Assuming that intelligent observers arise and observe, as in our Universe, the onset of dark-energy-driven acceleration following matter domination, and that this acceleration persists to the present, we derive nontrivial constraints on both the axion mass and the bare cosmological constant. The axion mass is bounded from above to avoid fine-tuning of the initial misalignment angle near the hilltop, and from below because too light axions cannot achieve accelerated expansion due to their limited energy budget. As a result, the anthropically allowed axion mass range typically lies around $m=\mathcal{O}(10)H_0$ for a decay constant close to the Planck scale, where $H_0$ is the observed value of the Hubble constant. In this framework, the dark energy equation-of-state parameter $w_0$ generically deviates from $-1$ by $\mathcal{O}(0.1)$, providing a natural explanation for why $w\ne -1$ may be expected. We also find that, for a decay constant slightly smaller than the Planck scale, the peak value of dark energy density is significantly smaller than the anthropic bound on the cosmological constant and can be close to the observed value. These outcomes are intriguingly consistent with recent DESI hints of time-varying dark energy, and offer a compelling anthropic explanation within the $\mathrm{\Lambda }+$ axion framework.

Thermal dark matter models generically include the prompt creation of highly concentrated dark matter cusps in the early Universe. Recent studies find that these cusps can survive to the present day, as long as they do not fall into extremely dense regions of baryonic structure. In this work, we build models of dark matter annihilation within the prompt cusps that reside in galaxy clusters, showing that they dominate the total $\gamma$-ray annihilation signal. Using 15 years of Fermi Large Area Telescope data, we find no evidence for a $\gamma$-ray excess from these sources, and set strong constraints on annihilating dark matter. These constraints generically rule out the thermal annihilation cross section to the $b\overline{b}$ channel for dark matter masses below $\sim 200\mathrm{GeV}$.

In this work the production of the state $X(3872)$ is estimated via the reaction $B^0\to K^{*0}X(3872)$ through triangle mechanisms described by the sequence $B^0\to D_s^{(*)+}(\to K^{*0}{D}^{(*)+})D^{(*)-}\to K^{*0}(D^{(*)+}{D}^{(*)-})\to K^{*0}X(3872)$. The molecular configuration $(D{\overline{D}}^{*}-\mathrm{c}.\mathrm{c}.)$ of the $X(3872)$ is considered. By means of the effective Lagrangian approach, the branching ratio $\mathcal{B}(B^0\to K^{*0}X(3872))$ is calculated as a function of the strength of the coupling of the charged components $(D^{+}{\overline{D}}^{*-}-\mathrm{c}.\mathrm{c}.)$ to the $X(3872)$ and compared with experimental data. Besides, employing the decay $B^0\to K^{*0}\psi (2S)$ as a normalization channel, the ratio of branching fractions $R=\frac{\mathcal{B}(B^0\to K^{*0}X(3872))}{\mathcal{B}(B^0\to K^{*0}\psi (2S))}\times \frac{\mathcal{B}(X(3872)\to J/\psi {\pi }^{+}{\pi }^{-})}{\mathcal{B}(\psi (2S)\to J/\psi {\pi }^{+}{\pi }^{-})}$ is also estimated. The findings provide another concrete example for the vital role of charged components in achieving a quantitatively correct description of the $X(3872)$.

We present a comprehensive tensor network study of staggered, Wilson, and twisted mass fermions in the Hamiltonian formulation, using the massive two-flavor Schwinger model as a benchmark. Particular emphasis is placed on twisted mass fermions, whose properties in this context have not been systematically explored before. We confirm the expected $\mathcal{O}(a)$ improvement in the free theory and observe that this improvement persists in the interacting case. By leveraging an electric-field-based method for mass renormalization, we reliably tune to maximal twist and establish the method’s applicability in the two-flavor model. Once mass renormalization is included, the pion mass exhibits rapid convergence to the continuum limit. Finite-volume effects are addressed using two complementary approaches: dispersion relation fits and finite-volume scaling. Our results show excellent agreement with semiclassical predictions and reveal a milder volume dependence for twisted mass fermions compared to staggered and Wilson discretizations. In addition, we observe clear isospin-breaking effects, suggesting intriguing parallels with lattice QCD. These findings highlight the advantages of twisted mass fermions for Hamiltonian simulations and motivate their further exploration—particularly in view of future applications to higher-dimensional lattice gauge theories.

We study the exotic ${\mathrm{\Delta }}^0{\mathrm{\Delta }}^0$ dibaryon state with quantum numbers $J^P=2^{+}$ within the framework of QCD sum rules. A tensor interpolating current is constructed to determine the mass and residue of this state, including explicit calculations of contributions from quark, gluon, and mixed vacuum condensates up to dimension nine. The numerical analysis yields a mass of $m_{{\mathrm{\Delta }}^0{\mathrm{\Delta }}^0}=2426_{-108}^{+101}\mathrm{MeV}$ and a residue of $f_{{\mathrm{\Delta }}^0{\mathrm{\Delta }}^0}=(2.30_{-0.45}^{+0.49})\times {10}^{-4}{\mathrm{GeV}}^8$. The predicted mass lies about 38 MeV below the $2m_{{\mathrm{\Delta }}^0}$ threshold, which indicates the possible existence of a bound configuration. Consequently, the tensor ${\mathrm{\Delta }}^0{\mathrm{\Delta }}^0$ dibaryon may serve as a promising candidate for future experimental searches.

The tiny neutrino masses are most naturally explained by seesaw mechanism through singlet right-handed neutrinos, which can further explain the matter-antimatter asymmetry in the Universe. In this work, we propose a new approach to study cosmological signatures of neutrino seesaw through the interaction between inflaton and right-handed neutrinos, which respects the shift symmetry. In our framework, after inflation the inflaton predominantly decays into right-handed neutrinos and its decay rate is modulated by the fluctuations of the Higgs field, which act as the source of curvature perturbations. This gives a new realization of Higgs modulated reheating, and it produces primordial non-Gaussian signatures that can be measured by the forthcoming large-scale structure surveys. We demonstrate, for the first time, that the measurements of non-Gaussianity by these surveys can probe the neutrino seesaw scale and have the potential to constrain a large portion of the seesaw parameter space, opening up a new window for directly testing the high-scale seesaw mechanism.

The ever-increasing number of detections of gravitational waves from compact binaries by the Advanced LIGO and Advanced Virgo detectors allows us to perform ever-more sensitive tests of general relativity (GR) in the dynamical and strong-field regime of gravity. We perform a suite of tests of GR using the compact binary signals observed during the second half of the third observing run of those detectors. We restrict our analysis to the 15 confident signals that have false alarm rates $\le {10}^{-3}{\mathrm{yr}}^{-1}$. In addition to signals consistent with binary black hole mergers, the new events include GW200115_042309, a signal consistent with a neutron star–black hole merger. We find the residual power, after subtracting the best fit waveform from the data for each event, to be consistent with the detector noise. Additionally, we find all the post-Newtonian deformation coefficients to be consistent with the predictions from GR, with an improvement by a factor of $\sim 2$ in the $-1\mathrm{PN}$ parameter. We also find that the spin-induced quadrupole moments of the binary black hole constituents are consistent with those of Kerr black holes in GR. We find no evidence for dispersion of gravitational waves, non-GR modes of polarization, or post-merger echoes in the events that were analyzed. We update the bound on the mass of the graviton, at 90% credibility, to $m_g\le 2.42\times {10}^{-23}\mathrm{eV}/c^2$. The final mass and final spin as inferred from the premerger and postmerger parts of the waveform are consistent with each other. The studies of the properties of the remnant black holes, including deviations of the quasinormal mode frequencies and damping times, show consistency with the predictions of GR. In addition to considering signals individually, we also combine results from the catalog of gravitational waves signals to calculate more precise population constraints. We find no evidence in support of physics beyond general relativity.

The effective field theory–based full-shape analysis with simulation-based priors (EFT-SBP) provides a unified framework that combines the strengths of perturbation theory and simulation-based modeling for galaxy clustering analyses. We apply EFT-SBP to the galaxy power spectrum and bispectrum measurements from the BOSS survey to test the recent preference for dynamical dark energy reported by the DESI Collaboration. While the combination of DESI baryon acoustic oscillation, Planck cosmic microwave background, and $\mathrm{Pantheon}+$ supernovae data favors a deviation from a cosmological constant, this preference is not supported when these data are combined with the BOSS EFT full-shape likelihood, which yields $w_0=-0.88\pm 0.11$ and $w_a=-0.34\pm 0.40$ at 95% CL for the dark energy equation of state parameters. Incorporating simulation-based priors in this analysis further tightens the constraints on dynamical dark energy by concentrating the posterior around the cosmological constant region and yielding $w_0=-0.91\pm 0.10$ and $w_a=-0.09\pm 0.35$ at 95% CL. The resulting figure of merit for the dark energy parameters improves by approximately 20% compared with the standard EFT full-shape analysis using conservative Gaussian priors. This improvement arises from modeling the EFT prior distribution with Gaussian mixture models, which accurately capture the non-Gaussian structure of simulation-based priors while preserving the ability to perform analytic marginalization over most EFT nuisance parameters. These results indicate that EFT-SBP provides an efficient and consistent framework for integrating simulation-based information into cosmological parameter inference and for testing extensions beyond $\mathrm{\Lambda }\mathrm{CDM}$.

Cosmic Microwave Background (CMB) photons scatter off the free-electron gas in galaxies and clusters, allowing us to use the CMB as a backlight to probe the gas in and around low-redshift galaxies. The thermal Sunyaev-Zel’dovich effect, sourced by hot electrons in high-density environments, measures the thermal pressure of the target objects, shedding light on halo thermodynamics and galaxy formation, and providing a path toward understanding the baryon distribution around cosmic structures. We use a combination of high-resolution CMB maps from the Atacama Cosmology Telescope and photometric luminous red galaxy catalogs from the Dark Energy Spectroscopic Instrument to measure the thermal Sunyaev-Zel’dovich signal in four redshift bins from $z=0.4$ to $z=1.2$, with a combined detection significance of $19\sigma$ when stacking on the fiducial CMB Compton-$y$ map. We discuss possible sources of contamination, finding that residual dust emission associated with the target galaxies is important and limits current analyses. We discuss several mitigation strategies and quantify the residual modeling uncertainty. This work complements closely related measurements of the kinematic Sunyaev-Zel’dovich and weak lensing of the same galaxies.