物理最新文献

Systematic comparisons across theoretical predictions for the properties of dense matter, nuclear physics data, and astrophysical observations (also called meta-analyses) are performed. Existing predictions for symmetric nuclear and neutron matter properties are considered, and they are shown in this paper as an illustration of the present knowledge. Asymmetric matter is constructed assuming the isospin asymmetry quadratic approximation. It is employed to predict the pressure at twice saturation energy-density based only on nuclear-physics constraints, and we find it compatible with the one from the gravitational-wave community. To make our meta-analysis transparent, updated in the future, and to publicly share our results, the Python toolkit nucleardatapy is described and released here. Hence, this paper accompanies nucleardatapy, which simplifies access to nuclear-physics data, including theoretical calculations, experimental measurements, and astrophysical observations. This Python toolkit is designed to easily provide data for: (i) predictions for uniform matter (from microscopic or phenomenological approaches); (ii) correlation among nuclear properties induced by experimental and theoretical constraints; (iii) measurements for finite nuclei (nuclear chart, charge radii, neutron skins or nuclear incompressibilities, etc.) and hypernuclei (single particle energies); and (iv) astrophysical observations. This toolkit provides data in a unified format for easy comparison and provides new meta-analysis tools. It will be continuously developed, and we expect contributions from the community in our endeavor.

This investigation analyzes the angular distributions (ADs) for the ⁷Li + ¹³⁸Ba elastic scattering system across laboratory energies of 21–32 MeV using multiple nuclear potential approaches. Several computational methods were applied to assess the relative impacts of ⁷Li breakup and neutron transfer processes, particularly examining how the ¹³⁸Ba(⁷Li,⁶Li)¹³⁹Ba stripping reaction affects the elastic scattering channel. Our calculations demonstrate that ⁷Li breakup dominates over neutron transfer contributions in this system. Volume integrals for the real and imaginary potentials near the Coulomb barrier yield evidence for the existence of a breakup threshold anomaly.

The measurement of (Sigma ^{+}) production in pp collisions at (sqrt{s}=13) TeV is presented. The measurement is performed at midrapidity in both minimum-bias and high-multiplicity pp collisions at (sqrt{s} =13) TeV. The (Sigma ^{+}) is reconstructed via its weak-decay topology in the decay channel (Sigma ^{+} rightarrow mathrm{{p}} + pi ^{0}) with (pi ^{0} rightarrow gamma + gamma .) In a novel approach, the neutral pion is reconstructed by combining photons that convert in the detector material with photons measured in the calorimeters. The transverse-momentum ((p_{textrm{T}})) distributions of the (Sigma ^{+}) and its rapidity densities ({textrm{d}}N)/({textrm{d}}y) in both event classes are reported. The (p_{textrm{T}}) spectrum in minimum-bias collisions is compared to QCD-inspired event generators. The ratio of (Sigma ^{+}) to previously measured (Lambda ) baryons is in good agreement with calculations from the Statistical Hadronization Model. The high efficiency and purity of the novel reconstruction method for (Sigma ^{+}) presented here will enable future studies of the interaction of (Sigma ^{+}) with protons in the context of femtoscopic measurements, which could be crucial for understanding the equation of state of neutron stars.

Pulsars convert a significant fraction of their total spin-down power into very high-energy electrons, leading to the formation of TeV halos. While these halos are well characterized at TeV energies, it remains unclear whether pulsars also accelerate electrons efficiently at lower energies and how these particles propagate through their surrounding environments. We aim to test whether synchrotron emission from (sim 50)–(300 , textrm{GeV}) electrons around the Geminga pulsar can be detected in the frequency range observed by the Planck satellite. This would help constrain low-energy particle acceleration and diffusion in the vicinity of pulsars. We model the expected synchrotron emission from Geminga’s TeV halo based on various diffusion and injection spectrum scenarios and compare these predictions to publicly available multi-frequency Planck data. We find no conclusive evidence of spatially extended synchrotron emission associated with Geminga in any of Planck’s frequency bands. Our calculations show that even under favorable diffusion and injection conditions, the predicted synchrotron flux lies well below Planck’s measured background levels.

Hidden-charm pentaquark states with double strangeness, (P_{css}), have been predicted within the framework of unitary coupled-channel dynamics. In this work, we theoretically investigate the potential to observe these states in the decays (Lambda _brightarrow J/psi Xi ^-K^+) and (Xi _brightarrow J/psi Xi ^-pi ^+). In this framework, these pentaquark configurations couple strongly to the (J/psi Xi ) channel, as well as to other vector-baryon channels with the (bar{c} c s s n) flavor structure, making these decay modes promising for their observation through the corresponding invariant-mass distributions. Our analysis begins with the identification of the dominant weak decay mechanisms, followed by hadronization into meson-baryon channels, connected through flavor symmetry. Final-state interactions are then incorporated to dynamically generate the full amplitude, accounting for the formation of the pentaquark states. We compare our results with recent LHCb measurements of the (J/psi Xi ^-) mass distribution and find that, given the predicted pentaquark width of about 10 MeV in this channel, the state is too narrow to be resolved with the current experimental resolution, but it would become visible with significantly improved mass precision.

We introduce a new methodology to characterize properties of quantum spacetime in a strongly quantum-fluctuating regime, using tools from topological data analysis. Starting from a microscopic quantum geometry, generated nonperturbatively in terms of dynamical triangulations (DT), we compute the Betti numbers of a sequence of coarse-grained versions of the geometry as a function of the coarse-graining scale, yielding a characteristic “topological finger print”. We successfully implement this methodology in Lorentzian and Euclidean 2D quantum gravity, defined via lattice quantum gravity based on causal and Euclidean DT, yielding different results. Effective topology also enables us to formulate necessary conditions for the recovery of spacetime symmetries in a classical limit.

We perform a systematic analysis of the (Lambda _b rightarrow Lambda ) transition form factors using the perturbative QCD (PQCD) approach, taking into account contributions from higher-twist light-cone distribution amplitudes (LCDAs). Using inputs from lattice QCD, we show that the baryon higher-twist LCDAs give numerically dominant contributions to the form factors. By combining our PQCD results at low-(q^2) region with lattice QCD predictions at high (q^2,) we carry out z-series expansion fits to obtain a unified description of the form factors over the full physical kinematic range. We also provide predictions for physical observables in the rare decay (Lambda _b rightarrow Lambda mu ^+ mu ^-,) such as the differential branching fraction, the longitudinal polarization fraction of the dimuon system, and the forward–backward asymmetries.

The spin-curvature coupling in the Mathisson–Papapetrou–Dixon (MPD) formalism induces non-geodesic motion, shifting the orbital parameters of spinning test particles in black hole spacetimes. We investigate whether these quantitative shifts alter the qualitative, global structure of the orbit manifold. Using a topological approach, we study timelike circular orbits (TCOs) for spinning particles in static, spherically symmetric spacetimes. By constructing an auxiliary vector field, we compute the topological winding number W in horizon-bounded regions of asymptotically flat, anti-de Sitter (AdS), and de Sitter (dS) backgrounds. We find that W is robust against both the magnitude and direction of the particle’s spin: between two horizons, (W = -1,) guaranteeing at least one unstable TCO; outside the outermost horizon in asymptotically flat and AdS spacetimes, (W = 0,) enforcing that TCOs must appear in stable–unstable pairs or be absent. This spin independence reveals that the fundamental orbital structure is a property of spacetime geometry itself, not of the particle’s spin. We validate this with quantitative examples in Schwarzschild, Schwarzschild–AdS, and Schwarzschild–dS spacetimes, showing explicit spin-induced TCO shifts while confirming the invariant topology. This result provides a topological foundation for interpreting gravitational waveforms from extreme mass-ratio inspirals involving spinning secondaries.

In this study, F/Cu/V_Zn/H_i multi-defect coupled ZnS systems were innovatively constructed, and the regulatory mechanisms of their structure, magnetism, conductivity type, and photocatalytic CO₂ reduction performance were systematically investigated. Structural stability of the systems is significantly enhanced by the synergistic introduction of F/Cu/H_i (formation energy as low as − 4.376 eV). Magnetism of the systems originates from unpaired spin electrons in the Cu^2-3d⁹ orbital, with a magnetic moment contribution of 1 μ_B. A regular transition of magnetic moment spin distribution from localized states (Cu²⁺-S²⁻) to delocalized states (Zn-4s) is observed with increasing F⁻ concentration. Different conductivity types can be achieved via precise regulation of F⁻ concentration (n-type at 4.23% F⁻, p-type at 1.41%/2.82% F⁻). The optimized n-type system exhibits a narrow band gap (1.78 eV), broad spectral response (strong absorption in visible-infrared region), low electronic effective mass (0.20 m₀), and high average hole-electron effective mass ratio (({bar{text{D}}}) = 3.54). Its conduction band minimum energy level is precisely matched with the potential for CO₂ reduction to CH₄, and CO₂ adsorption/activation efficiency is significantly enhanced by the short-range synergistic effect between V_Zn and F⁻. ZnS-based functional materials with tunable magnetism, controllable conductivity type, and high-efficiency photocatalytic performance are successfully constructed, providing new insights and experimental support for the design of high-performance materials for spintronic devices and photocatalytic CO₂ reduction cells.

Graphical abstarct

In this study, we investigate the thermodynamic stability and geometric thermodynamics of the regular Bardeen-AdS black hole within the framework of Kaniadakis statistics, incorporating the (kappa )-deformed entropy. By varying both the Kaniadakis parameter (kappa ) and the black hole parameters, we uncover additional (kappa )-dependent thermodynamic branches, singularities, and divergence points that are absent in the standard ((kappa = 0)) case. The physical relevance of these new features is confirmed through geometric thermodynamics: curvature scalars computed from both the Quevedo geometrothermodynamic (GTD) and HPEM metrics precisely coincide with the phase transition points and divergence points identified from heat capacity and free energy analyses. Furthermore, the equation of state in the pressure-horizon radius plane reveals (kappa )-dependent critical behavior, consistent with the extended phase space analysis. The complete agreement among canonical, extended, and geometric thermodynamic diagnostics demonstrates that the (kappa )-induced branches correspond to physically distinct phases, providing a robust, (kappa )-dependent extension of the thermodynamic and phase structure of the Bardeen-AdS black hole.