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Nuclear Theory·nucl-th

Tuesday·March 25, 2025

13 papers—6 primary·7 cross-listed

All13Primary6Cross-lists7
  1. 01

    Charge-dependent nucleon-nucleon interaction at NLO in nuclear lattice effective field theory

    Chengxin Wu🇨🇳 · Teng Wang🇨🇳 · Bing-Nan Lu🇨🇳 · Ning Li🇨🇳

    The nuclear lattice effective field theory (NLEFT) is an efficient tool for solving nuclear many-body problems, which takes high-fidelity lattice chiral interactions as input and computes nuclear low-energy observables via quantum Monte Carlo techniques. In this work, we present the first next-to-next-to-next-to-leading order (NLO) chiral forces on the lattice with the isospin-breaking effects fully taken into account. We focus on both the charge-independence breaking (CIB) and charge-symmetry breaking (CSB) effects. Specifically, we include the isospin-breaking effect from the mass difference between the charged and neutral pions in the one-pion-exchange potential (OPEP), the Coulomb force for the interaction and the contribution of two additional charge-dependent contact operators. We also explicitly incorporate the two-pion-exchange potentials which was mostly neglected in previous NLEFT calculations. With these improvements, we are able to accurately reproduce the and scattering phase shifts up to relative momentum MeV as well as the deuteron properties. The construction of these charge-dependent lattice nuclear forces establishes a solid foundation for future high-precision nuclear ab initio calculations within the NLEFT framework.

    nucl-thhep-lathep-phnucl-exPRC(2025)·7 citations
  2. 02

    In-medium nucleon-nucleon cross sections from relativistic ab initio calculations

    Tianyu Wang · Hui Tong · Chencan Wang · Xiaoying Qu · Sibo Wang

    The in-medium nucleon-nucleon scattering cross section is a pivotal quantity for studying the medium effects of strong interaction, and its precise knowledge is critical for understanding the equation of state for dense matter, intermediate-energy heavy-ion collision dynamics, and related phenomena. In this work, we perform a microscopic investigation of in-medium nucleon-nucleon scattering cross sections, by utilizing the relativistic Brueckner-Hartree-Fock (RBHF) theory with the Bonn potential. The fully incorporation of both positive- and negative-energy states in the RBHF solutions allows us to determine the single-particle potentials, the effective G matrix, and the scattering cross section uniquely. The momentum, density, and isospin dependence of the cross section for pp, nn, and np scattering are studied in detail. Our results provide a solid foundation for future parametrization studies of multiparameter dependency of total scattering cross sections.

    nucl-thPRC(2025)·2 citations
  3. 03

    Effective field theory for weakly bound two-neutron halo nuclei: corrections from neutron-neutron effective range

    Davi B. Costa · Masaru Hongo · Dam Thanh Son

    Using an effective field-theoretical approach, we investigate the properties of weakly bound two-neutron halo nuclei (also known as Borromean nuclei) that do not support a low-energy -wave core-neutron resonance. Extending the recently formulated effective field theory for weakly bound Borromean nuclei, we incorporate corrections arising from the effective range of neutron-neutron scattering and evaluate their impact on the mean-square radii and electromagnetic response. In particular, we compute the ratio of the matter and charge radii, the shape of the dipole strength function, and the electric polarizability. Our results indicate that these corrections remain numerically small when the two-neutron separation energy of the Borromean nucleus is much less than 1~MeV.

    nucl-thcond-mat.quant-gashep-thPRC(2025)·4 citations
  4. 04

    Relativistic He light-front wave function

    V.A. Karmanov🇷🇺 · Zhimin Zhu🇨🇳 · Ziqi Zhang🇨🇳 · Kaiyu Fu🇨🇳

    The relativistic light-front (LF) wave function of He is determined by the three-body LF equation for the Faddeev components in the momentum space. As an interaction, we take the one-meson exchange kernels, without the potential approximation. Within the explicitly covariant formulation of LF dynamics, we calculate the full relativistic He LF wave function, comprising 32 spin-isospin components. In the non-relativistic domain, five of these components dominate and closely resemble their non-relativistic counterparts. Relativistic effects manifest themselves in deviations in relativistic domain of these components from the non-relativistic ones and in appearance of new components.

    nucl-thhep-phJ.Subatomic Part.Cosmol.(2025)·1 citation
  5. 05

    Generalized relativistic second-order dissipative hydrodynamics: coupling different rank tensors

    Arus Harutyunyan🇦🇲 · Armen Sedrakian🇵🇱

    In this work, we extend the formalism of second-order relativistic dissipative hydrodynamics, developed previously using Zubarev's non-equilibrium statistical operator formalism. By employing a second-order expansion of the statistical operator in terms of hydrodynamic gradients, we demonstrate that new second-order terms emerge due to the coupling of two-point quantum correlators between tensors of differing ranks, evaluated at distinct space-time points. Such terms arise because the presence of the acceleration vector in the system allows Curie's theorem, which governs symmetry constraints, to be extended for constructing invariants from tensors of different ranks evaluated at distinct space-time points. The new terms are identified in the context of a complete set of second-order equations governing the shear-stress tensor, bulk-viscous pressure, and charge-diffusion currents for a generic quantum system characterized by the energy-momentum tensor and multiple conserved charges. Additionally, we identify the transport coefficients associated with these new terms and derive the Kubo formulas expressing the second-order transport coefficients through two- and three-point correlation functions.

    nucl-thastro-ph.HEhep-phAnnals Phys.(2025)·3 citations
  6. 06

    Role of the Meson in the Equation of State an Direct Urca Cooling of Neutron Stars

    Luigi Scurto🇵🇹 · Helena Pais🇵🇹 · Marco Antonelli🇫🇷 · Francesca Gulminelli🇫🇷

    The direct Urca (dUrca) process is a key mechanism driving rapid neutrino cooling in neutron stars, with its baryon density activation threshold determined by the microscopic model for nuclear matter. Understanding how nuclear interactions shape the dUrca threshold is essential for interpreting neutron star thermal evolution, particularly in light of recent studies on exceptionally cold objects. We investigate the impact of incorporating the scalar isovector meson into the neutron star equation of state, which alters the internal proton fraction and consequently affects the dUrca cooling threshold. Since proton superfluidity is known to suppress dUrca rates, we also examine the interplay between the nuclear interaction mediated by the meson and the proton pairing gap. We perform a Bayesian analysis using models built within a relativistic mean-field approximation, incorporating constraints from astrophysical observations, nuclear experiments, and known results of \textit{ab initio} calculations of pure neutron matter. We then impose a constraint on the dUrca threshold based on studies of fast-cooling neutron stars. The inclusion of meson expands the range of possible internal compositions, directly influencing the stellar mass required for the central density to reach the dUrca threshold. Furthermore, we observe that the observation of relatively young and cold neutron stars provides insights into proton superfluidity in the core of neutron stars.

    nucl-thastro-ph.HEAstron.Astrophys.(2025)·7 citations

Affiliations

first authorsco-authorsvia INSPIRE