PaperPanorama

Nuclear Theory·nucl-th

Wednesday·June 11, 2025

12 papers5 primary·7 cross-listed

  1. 01

    Estimation of Electron Screening Potential in the 6Li(d,{\alpha})4He Reaction Using Multi-Layer Perceptron Neural Network

    D. Chattopadhyay

    Reactions between light charged nuclei at sub-Coulomb energies are crucial in astrophysical environments, but accurate cross-section measurements are hindered by electron screening. Traditional methods, including polynomial extrapolation and the Trojan Horse Method, often yield screening potentials exceeding adiabatic predictions. Building on the success of an MLP-based Artificial Neural Network (ANN) for the 6Li(p, {\alpha})3He reaction [1], this work applies the same approach to the 6Li(d, {\alpha})4He reaction. Experimental astrophysical S-factor data from literature are reanalyzed using the ANN to model the energy-dependent S-factor. The bare S-factor is extracted from data above 70 keV, where screening effects are minimal, and the screening potential is obtained by comparing with the low-energy region. The resulting screening potential is 147.95 eV, demonstrating the robustness of ANN-based methods for evaluating electron screening in low-energy nuclear reactions involving light nuclei.

    nucl-thRadiat.Phys.Chem.(2026)·0 citations
  2. 02

    Bulk Viscosity of Two-Flavor Color Superconducting Quark Matter in Neutron Star Mergers

    Mark Alford🇺🇸 · Arus Harutyunyan🇦🇲 · Armen Sedrakian🇵🇱 · Stefanos Tsiopelas🇵🇱

    This work investigates the bulk viscosity of warm, dense, neutrino-transparent, color-superconducting quark matter, where damping of density oscillations in the kHz frequency range arises from weak-interaction-driven direct Urca processes involving quarks. We study the two-flavor red-green paired color-superconducting (2SC) phase, while allowing for the presence of unpaired strange quarks and blue color light quarks of all flavors. Our calculations are based on the SU(3) Nambu-Jona-Lasinio (NJL) model, extended to include both vector interactions and the `t Hooft determinant term. The primary focus is on how variations in the NJL Lagrangian parameters -- specifically, the diquark and vector coupling strengths -- affect both the static properties of quark matter, such as its equation of state and composition, and its dynamical behavior, including bulk viscosity and associated damping timescales. We find that the bulk viscosity and corresponding damping timescale can change by more than an order of magnitude upon varying the vector coupling by a factor of two at high densities and by a lesser degree at lower densities. This sensitivity primarily arises from the susceptibility of 2SC matter, with a smaller contribution from modifications to the weak interaction rates. In comparison, changes in the diquark coupling have a more limited impact. The damping of density oscillations in 2SC matter is similar quantitatively to nucleonic matter and can be a leading mechanism of dissipation in merging hybrid stars containing color superconducting cores. -

    nucl-thastro-ph.HEFront.Astron.Space Sci.(2025)·10 citations
  3. 03

    Microscopic analysis of the giant monopole resonance excitation energy

    M.K. Gaidarov🇧🇬 · M.V. Ivanov🇧🇬 · Y.I. Katsarov🇧🇬 · A.N. Antonov🇧🇬 · I.C. Danchev🇮🇳

    A systematic study of the isoscalar giant monopole resonance (ISGMR) in a wide range of nuclei from various isotopic chains is performed within the microscopic self-consistent Skyrme HF+BCS method and coherent density fluctuation model (CDFM). The calculations for the nuclear incompressibility are based on the Brueckner and Barcelona-Catania-Paris-Madrid (BCPM) energy density functionals for nuclear matter using the capability of the CDFM to make a transition to the corresponding incompressibility in finite nuclei. The results obtained by applying of different definitions of the ISGMR energy, as well as the two energy-density functionals, are analyzed and compared with the available experimental data. The consideration includes the peculiarities of the proton and neutron density distributions and their corresponding linear size characteristics. In general, a connection with the measured neutron skin thicknesses is proposed as a possible way for realistic estimations of the energy of ISGMR.

    nucl-thPRC(2025)·1 citation
  4. 04

    Symmetry energy and neutron matter equation of state at from the electric dipole polarizability in Ca, Ni and Pb

    Mengying Qiu🇨🇳 · Lie-Wen Chen🇨🇳 · Zheng Zheng Li🇨🇳 · Yi Fei Niu🇨🇳 · Zhen Zhang🇨🇳

    Based on the quasiparticle random phase approximation implemented via the finite amplitude method, we employ a set of representative relativistic mean-field models to investigate the sensitivity of the inverse electric dipole polarizability in , , and to the symmetry energy and the neutron matter equation of state at a subsaturation density of . Combined with predictions from nonrelativistic Skyrme energy density functionals (EDFs), our results reveal strong linear correlations between and both and . In particular, the -- correlation for is found to be nearly model-independent. A Bayesian analysis of the measured values of in , , and yields quantitative constraints of and at the 68\% (90\%) confidence level, respectively. The extracted value of exceeds most predictions from microscopic many-body theories, suggesting a mild tension between nuclear EDF-based constraints derived from data and results from \textit{ab initio} calculations.

    nucl-thPRC(2025)·2 citations
  5. 05

    Heavy-heavy and heavy-light mesons in cold nuclear matter

    J. J. Cobos-Martínez🇲🇽 · Guilherme N. Zeminiani🇧🇷 · Kazuo Tsushima🇧🇷

    We review the in-medium modifications of effective masses (Lorentz scalar potentials or phenomenon of mass shift) of heavy-heavy and heavy-light mesons in symmetric nuclear matter and their nuclear bound states. We use a combined approach with the quark-meson coupling (QMC) model and an effective Lagrangian. As demonstrated by the cases of pionic and kaonic atoms, studies of meson-nucleus bound state can provide us with important information on chiral symmetry in dense nuclear medium. In this review, we treat the mesons, , and , where our emphasys is on the heavy mesons. In addition, we also present some new results for the -nucleus bound states.

    nucl-thhep-exhep-phnucl-exSymmetry(2025)·4 citations
  6. 06

    Dense Matter in Neutron Stars with eXTP

    Ang Li🇨🇳 · Anna L. Watts🇳🇱 · Guobao Zhang🇨🇳 · Sebastien Guillot🇫🇷 · Yanjun Xu🇨🇳 · Andrea Santangelo🇩🇪 · Silvia Zane🇬🇧 · Hua Feng🇨🇳 · Shuang-Nan Zhang🇨🇳 · Mingyu Ge🇨🇳 · Liqiang Qi🇨🇳 · Tuomo Salmi🇫🇮 and 73 other authors

    In this White Paper, we present the potential of the enhanced X-ray Timing and Polarimetry (eXTP) mission to constrain the equation of state of dense matter in neutron stars, exploring regimes not directly accessible to terrestrial experiments. By observing a diverse population of neutron stars - including isolated objects, X-ray bursters, and accreting systems - eXTP's unique combination of timing, spectroscopy, and polarimetry enables high-precision measurements of compactness, spin, surface temperature, polarimetric signals, and timing irregularity. These multifaceted observations, combined with advances in theoretical modeling, pave the way toward a comprehensive description of the properties and phases of dense matter from the crust to the core of neutron stars. Under development by an international Consortium led by the Institute of High Energy Physics of the Chinese Academy of Sciences, the eXTP mission is planned to be launched in early 2030.

    astro-ph.HEastro-ph.SRhep-phnucl-thSCPMA(2025)·48 citations
  7. 07

    Wave-function microscopy: Derivation and anatomy of exact algebraic spinful wave functions and full Wigner-molecular spectra of a few highly correlated rapidly rotating ultracold fermionic atoms

    Constantine Yannouleas · Uzi Landman

    Exploring strongly correlated spinful states of few fermionic ultracold atoms in a rapidly rotating trap, an example of which was recently realized for two fermionic Li atoms in an optical tweezer, we derive analytical (algebraic) total-spin-eigenstate wavefunctions through the development and employment of a theoretical platform that integrates exact numerical diagonalization (full configuration interaction, FCI) with symbolic language processing. For such rapid rotations, where the atoms occupy the lowest Landau level (LLL), the obtained algebraic expressions can address the full LLL spectrum in all its complexity, demonstrating that their spatial, spectral, and spin characteristics manifest formation of collectively rotating and vibrating Wigner molecules. The explicitly exhibited analytic wavefunctions (for two and three spinful Li atoms) reproduce precisely the corresponding numerical FCI results, and they are shown to reach beyond the limited range of applicability of previous Jastrow-type treatments. These results, and their extension to bosonic systems, provide the impetus and analysis tools for future experimental and theoretical simulations of larger mesoscopic systems

    cond-mat.quant-gasnucl-thquant-phPRA(2025)·0 citations
  8. 08

    Revealing Dark Matter's Role in Neutron Stars Anisotropy: A Bayesian Approach Using Multi-messenger Observations

    Xue-Zhi Liu🇨🇳 · Premachand Mahapatra🇮🇳 · Chun Huang🇺🇸 · Ayush Hazarika🇮🇳 · Chiranjeeb Singha🇮🇳 · Prasanta Kumar Das🇮🇳

    Dark matter (DM) continues to evade direct detection, but neutron stars (NSs) serve as natural laboratories where even a modest DM component can alter their structure. While many studies have examined DM effects on NSs, they often rely on specific choices of equations of state (EOS) models, assume isotropy, and lack a Bayesian statistical framework, limiting their predictive power. In this work, we present a Bayesian framework that couples pressure-anisotropic nuclear EOS to a self-interacting fermionic DM component, constrained by NICER and GW170817 data. Our results show that DM mass fractions up to remain consistent with current data, which softens the high-density EOS, leading to reduced stellar radii and tidal deformabilities while requiring negligible pressure anisotropy. Bayesian model comparison reveals no statistically significant preference between pure baryonic and DM-admixed NSs, indicating that DM inclusion enhances physical realism without complexity penalties. However, existing data cannot tightly constrain the DM parameters, and our empirical radius definition introduces a systematic bias toward the DM core configurations. To address this, we therefore introduce the DM radius span as a unified diagnostic for DM distributions. This parameter simultaneously characterizes core-halo transition features while exhibiting strong linear correlations () with both DM and BM parameters, providing a clear avenue for future constraints. Our approach bridges current limitations and future potential in probing DM through compact star observations.

    astro-ph.HEgr-qcnucl-thPRD(2025)·12 citations
  9. 09

    Crust (Unified) Tool for Equation-of-state Reconstruction (CUTER) v2

    P. J. Davis🇫🇷 · H. Dinh Thi🇺🇸 · A. F. Fantina🇫🇷 · F. Gulminelli🇫🇷 · M. Oertel🇫🇷 · L. Suleiman🇺🇸

    The equation of state (EoS) is a needed input to determine the neutron-star global properties and to relate them. It is thus important to provide consistent and unified EoSs to avoid possible biases in the analyses coming from the use of inconsistent EoSs. We propose a numerical tool, CUTER, allowing the user to consistently match a nuclear-physics informed crust to an arbitrary higher density EoS. We present here the second version of this tool, CUTER v2. Two functionalities are available with the CUTER v2 tool, allowing the user to reconstruct either the whole (outer and inner) crust, or the outer crust only. We show that the code, that has been tested and validated for use by the astrophysical community, is able to efficiently perform both tasks, allowing the computation of neutron-star global properties in a consistent way.

    astro-ph.HEnucl-thEPJA(2025)·8 citations
  10. 10

    and mesons in isospin asymmetric nuclear medium

    Anshu Gautam🇮🇳 · Dhananjay Singh🇮🇳 · Navpreet Kaur🇮🇳 · Satyajit Puhan🇮🇳 · Suneel Dutt🇮🇳 · Harleen Dahiya🇮🇳 · Arvind Kumar🇮🇳

    We investigate the properties of pseudoscalar and vector mesons in an isospin asymmetric nuclear medium using a hybrid approach that integrates the light-front quark model with the chiral SU(3) quark mean field model. The influence of isospin asymmetric nuclear medium is examined by utilizing the in-medium quark masses derived from the chiral SU(3) quark mean field model as an input in the light-front quark model to study the medium modification of mesons. We examine the impact of isospin asymmetry and baryon density at zero and finite temperature on the effective masses, weak decay constants, and distribution amplitudes of the pseudoscalar mesons , , , and the vector mesons , , and . Our results indicate significant medium-induced changes for pseudoscalar and vector mesons having as one of their constituent quarks, while a comparatively reduced effect is observed for mesons containing a strange quark. In contrast to temperature and isospin asymmetry, changes in the baryon density of the nuclear medium have a larger effect on different properties of and mesons.

    hep-phnucl-thPTEP(2025)·1 citation
  11. 11

    Modern approach to muonic x-ray spectroscopy demonstrated through the measurement of stable Cl radii

    K.A. Beyer🇩🇪 · T.E. Cocolios🇧🇪 · C. Costache🇷🇴 · M. Deseyn🇧🇪 · P. Demol🇧🇪 · A. Doinaki🇨🇭 · O. Eizenberg🇮🇱 · M. Gorshteyn🇩🇪 · M. Heines🇧🇪 · A. Herzáň🇸🇰 · P. Indelicato🇫🇷 · K. Kirch🇨🇭 and 16 other authors

    Recent advances in muonic x-ray experiments have reinvigorated efforts in measurements of absolute nuclear charge radii. Here, a modern approach is presented, and demonstrated through determination of the charge radii of the two stable chlorine nuclides Cl and Cl. Knowledge of these radii has implications for fundamental studies in nuclear and atomic physics. For this purpose, a state-of-the-art experiment was performed at the E1 beamline in the Paul Scherrer Institute (Switzerland), using a large-scale HPGe detector array in order to extract precise energies of the muonic Cl and Cl transitions. The nuclear charge radius extraction relies on modern calculations for QED effects and nuclear polarization with rigorous uncertainty quantification, including effects that were not accounted for in older studies. Additionally, we established a new method for applying the nuclear shape correction directly from energy density functionals, which are amenable to isotopes for which no high-quality electron scattering experiments are available. The resulting charge radii are for Cl and for Cl, thus improving the uncertainty of the available electron scattering values by a factor of seven. The correlation of several observables was evaluated between the different isotopes in order to produce a more precise value of the differential mean square charge radius . In this case, improvement of the uncertainty by more than one order of magnitude was achieved compared to the literature value. This precision is sufficient to use this differential as input for isotope shift factor determination.

    nucl-exnucl-thphysics.atom-phphysics.data-an7 citations
  12. 12

    Entanglement Suppression, Quantum Statistics and Symmetries in Spin-3/2 Baryon Scatterings

    Tao-Ran Hu🇨🇳 · Katsuyoshi Sone🇯🇵 · Feng-Kun Guo🇨🇳 · Tetsuo Hyodo🇯🇵 · Ian Low🇺🇸

    We explore the interplay among entanglement suppression, quantum statistics and enhanced symmetries in the non-relativistic -wave scattering involving the lowest-lying spin-3/2 baryons, which can be considered as four-dimensional qudits. These baryons form a ten-dimensional representation (decuplet) under the light-flavor symmetry and, in this limit, are considered indistinguishable under strong interactions. Treating the -matrix in the spin-3/2 baryon-baryon scattering as a quantum logic gate in the spin space, we study the consequence of entanglement suppression and compute the entanglement power of the -matrix. When the entanglement power vanishes, the -matrix is either an Identity or a SWAP gate and spin-flavor symmetries and/or non-relativistic conformal invariance emerge, as previously observed in spin-1/2 baryons. In the case of scattering identical particles, the entanglement power never vanishes due to constraints from spin statistics, which we interpret as projection-valued measurements onto symmetric or antisymmetric Hilbert space and define the entanglement power accordingly. When the entanglement power is non-vanishing but sits at a global or local minimum, enhanced symmetries still emerge and the -matrix can be interpreted as an Identity or a SWAP gate acting on the restricted Hilbert space allowed by quantum statistics. In general, when scattering identical spin- particles, we identify an enhanced symmetry for the Identity gate.

    hep-phhep-thnucl-thquant-phPRResearch(2025)·27 citations

Affiliations

first authorsco-authorsvia INSPIRE