物理最新文献

We investigate two-body non-leptonic (Drightarrow SS) weak decays, where S denotes a light scalar meson such as (a_0/a_0(980),) (f_0/f_0(980),) or (sigma _0/f_0(500).) Short-distance topologies from W-boson emission and annihilation (exchange) are found to be negligible, while long-distance final-state interactions provide the dominant contributions. In particular, triangle rescattering processes, (D rightarrow pi eta ^{(prime )} rightarrow sigma _0 a_0) and (D rightarrow a_1(1260)eta rightarrow sigma _0 a_0,) mediated by pion exchange in (pi eta ^{(prime )}) and (a_1(1260)eta ) scatterings, respectively, are identified as the leading mechanisms. Our calculations yield branching fractions ({mathcal {B}}(D_s^+ rightarrow sigma _0 a_0^+) = (1.0 pm 0.2^{+0.1}_{-0.2}) times 10^{-2},) ({mathcal {B}}(D^+ rightarrow sigma _0 a_0^+) = (1.1 pm 0.2^{+0.1}_{-0.2}) times 10^{-3},) and ({mathcal {B}}(D^0 rightarrow sigma _0 a_0^0) = (0.9 pm 0.2^{+0.2}_{-0.3}) times 10^{-5}.) For the Cabibbo-allowed decay mode (D_s^+ rightarrow f_0 a_0^+,) the near-threshold condition (m_{D_s}simeq m_{f_0}+m_{a_0}) limits the phase space, suppressing the branching fraction to ((3.4pm 0.3^{+0.4}_{-0.9})times 10^{-4}.) These results highlight rescattering-induced (Drightarrow SS) decays as promising channels for experimental studies at BESIII, Belle(-II), and LHCb.

Cosmological implications of a class of hybrid metric-Palatini gravity with a non-minimal matter-geometry coupling is considered. The theory contains a metric curvature tensor, together with a curvature tensor constructed from an independent affine connection. We will show that the model could be written as a bi-scalar–tensor gravity with a non-minimal coupling between matter sector and a scalar field. The theory will then be confronted with observational data from Cosmic Chronometers, BAO dataset from DESI and the Pantheon(^+) dataset. We will show that the theory could be a good alternative to the (Lambda )CDM model with the difference that the conservation of the baryonic matter sector holds only at the background level. The statefinder analysis will also be applied to the theory and it is observed that the DE behavior of the theory exhibits a quintessence to phantom transition occurs at redshifts around (zapprox 0.86).

This study presents computational results for the proton radiative capture by triton ((^3mathrm H)) using the Argonne V18 (AV18) potential model enhanced with three-body forces. We develop a comprehensive computational framework combining the AV18 nucleon–nucleon potential with Urbana IX three-nucleon forces to calculate the astrophysical S-factor, scattering length and effective range for the (^3mathrm H(p, gamma )^4He) reaction. Our methodology involves solving the Schrödinger equation numerically using variational Monte Carlo (VMC) techniques with explicit treatment of three-body correlations. The results show improved agreement with the experimental data compared to the two-body potential models, particularly in the low-energy region relevant for astrophysical applications. We provide detailed comparisons with previous theoretical studies and experimental measurements, demonstrating the importance of three-body forces in accurately describing this radiative capture process.

The intersection of machine learning and art authentication has emerged as a transformative area within the field of art analysis. This paper explores the application of various machine learning techniques to enhance the efficiency of art authentication processes. Two procedures with potential use in the identification of forgeries are discussed. The supervised one uses attribution markers collected in an extensive analysis of paintings as input to a classification model. The resulting classifier should aid an art expert in the final assessment of authenticity. The unsupervised method is easier to carry out, as it does not require labeled training data. It may help to identify forged artworks as outliers in the dataset by measuring their similarities to authentic objects. The methods are tested on paintings attributed to M. Willmann and A. Grottger, respectively. Our findings open up new avenues for research and exploration at the intersection of the art world and machine learning. They also emphasize the importance of a collaborative approach that integrates traditional art historical expertise with advanced computational methods, thereby enriching the understanding of artworks and enhancing the efficacy of authentication practices.

Graphical abstract

In this paper, the quantum corrections to the kinematics of geometry, specifically geodesics, are presented. This is done by employing the path integral over the geodesics. Interestingly, the geodesics do not see any modifications in this framework. However for the distances, it is demonstrated that these quantum corrections exhibit distinct behaviors for time-like, light-like, and space-like geodesics. For time-like geodesics, the maximum correction is the Planck length, which disappears when the classical separation vanishes. The light-like geodesics do not exhibit quantum corrections, meaning that the causal light cone remains the same in both classical and quantum frameworks under certain conditions. The quantum corrections for space-like geodesics impose a minimum on space-like separation, potentially playing a role in removing singularities by preventing null congruences from being closer than the Planck length. This framework also explores the correspondence between space-like/time-like geodesics and quantum/statistical physics.

This study presents a new model of anisotropic quintessence compact stars within the framework of 5-dimensional Einstein–Gauss–Bonnet gravity (EGBG). To analyze the interior structure of the stellar configuration, we employ a static and spherically symmetric line element to derive the corresponding field equations in EGBG. The generalized Tolman–Kuchowicz metric potential is adopted to obtain exact solutions of the governing equations. By applying the continuity conditions at the boundary, we determine the numerical values of the constants appearing in the metric ansatz, using observational data for the mass and radius of the compact star. A comprehensive physical analysis is carried out by evaluating several key physical requirements to ensure the viability of the model. To this end, we derive analytical expressions for relevant physical quantities and present their graphical behavior. The stability of the model is assessed through the adiabatic index and Herrera’s cracking concept based on sound speed analysis. The effects of the Gauss–Bonnet coupling parameter (alpha), as well as the parameter n introduced via the generalized metric ansatz, are thoroughly examined. Furthermore, we explore the mass–radius relationship to evaluate the compactness factor and surface redshift of the stellar configuration. This comprehensive approach ensures that the proposed stellar model satisfies the fundamental physical criteria required for a realistic and stable compact object. Overall, the study enhances our understanding of dense astrophysical bodies and supports the development of EGBG theory, thereby paving the way for future investigations in this domain.

The minimal supergravity framework is applied to a construction of new D-type single-field models of inflation in agreement with precision measurements of the cosmic microwave background radiation by Planck Collaboration, BICEP/Keck Collaboration, Atacama Cosmology Telescope and South Pole Telescope. The inflaton potential, the power spectrum of scalar perturbations, the cosmological observables and the reconstruction procedure can be very simple when using the e-folds as the running variable.