Nuclear Theory·nucl-th

Monday·August 4, 2025

12 papers—5 primary·7 cross-listed

01
Exploring Shell Evolution and N = 40 Magicity in Light-Mass Nuclei with Relativistc Mean Field Approach
Priyanka Saini · Praveen K. Yadav · M. S. Mehta · M. Bhuyan
We employ the relativistic mean-field (RMF) approach with NL3 parameters to study shell and sub-shell closures in the isotopic chains of Cl, Ar, K, Ca, Sc, Ti, V, and Cr nuclei. By analyzing nuclear bulk properties, binding energy, charge radii, two-neutron separation energies, deformation parameters ( $β_{2}$ ), and single-particle levels we trace the evolution of magic numbers. Our results highlight the single-particle energy levels to examine nuclear shell closure and the occupancy of individual nucleon orbitals. A comprehensive picture of N = 34 shell closure is particularly prominent in the isotopic chains of Cl, Ar, and Ti nuclei, where the magicity associated with this number remains evident across several isotopes. In contrast, the N = 40 exhibits a more robust and widespread manifestation across all the examined nuclei, indicating that its shell closure is less sensitive to the specific isotopic environment and more universally applicable across the given nuclear systems. To further validate these closures, we apply the coherent density fluctuation model (CDFM) to assess isospin-dependent observables, such as the symmetry energy and its surface and volume components. A systematic analysis of the symmetry energy, computed using the relativistic mean-field (RMF) approach, maps the evolution of the shell structure at $N = 20$ and 28, supports sub-magicity at $N = 34$ , and strongly suggests a shell closure at $N = 40$ , reflected consistently in both bulk and surface properties. The interplay between shell structure and nuclear deformation remains a central topic of research, and future theoretical and experimental studies will continue to shed light on the complex behaviour of these fascinating systems.
nucl-th0 citations
02
Implication of neutron star observations to the origin of nucleon mass
Bikai Gao🇯🇵 · Xiang Liu🇯🇵 · Masayasu Harada🇯🇵 · Yong-Liang Ma🇨🇳
We investigate the implications of neutron star observations for understanding the origin of nucleon mass using a framework that combines three complementary approaches: the equation of state based on parity doublet structure for hadronic matter below $2 n_{0}$ , the Nambu-Jona-Lasinio (NJL) model for quark matter above $5 n_{0}$ , and a model-independent analysis of the intermediate density region based on fundamental physical principles. By systematically exploring parameter spaces and comparing theoretical predictions with recent observational constraints, we establish constraints on the chiral invariant mass. Our results suggest that more than a half of the nucleon mass originates from sources beyond spontaneous chiral symmetry breaking, challenging conventional understanding of nucleon mass generation. These constraints arise solely from fundamental physical principles and observational data, independent of specific assumptions about the nature of the quark-hadron transition, providing robust insights into the microscopic origin of hadron masses.
nucl-thastro-ph.HEastro-ph.SRhep-ph+1SCPMA(2026)·9 citations
03
Nonlocal {\it in-medium} effective interaction for nucleon scattering off isospin-asymmetric targets
J. I. Fuentealba-Bustamante · H.F. Arellano
We have investigated the role of isospin asymmetry of the $N N$ effective interaction in the context of $N A$ elastic scattering. To this purpose we represent the {\it in-medium} $g$ matrix as an admixture of isospin-symmetric nuclear matter and pure neutron matter solutions of Brueckner-Hartree-Fock equations for infinite nuclear matter, denoted as $g [ρ, β]$ . We use the Argonne $v_{18}$ bare potential to represent the $N N$ interaction in free space, due to its ability to describe the $N N$ scattering amplitudes up to 350 MeV. The density-dependent isospin-asymmetric $g$ matrices are then used to calculate optical model potentials for elastic nucleon scattering off closed-shell nuclei. For this aim, we make use of the Arellano-Bauge $δ g$ -folding approach suited for an explicit treatment of nonlocal density matrices. This approach allows to account for the local isospin-asymmetry and density dependence of the {\it in-medium} $N N$ interaction. The resulting optical potentials are nonlocal since the entire nonlocal structure of the $g$ matrix is retained. We observe that including the isospin asymmetry in the $g$ matrix allows for a reasonable description of differential cross-sections at nucleon beam energies between 40 and 200 MeV. In the case of proton scattering at energies below $\sim$ 65 MeV, at momentum transfers $q$ below $\sim$ 1 fm $^{- 1}$ , the inclusion of neutronic-matter $g$ matrices yields better agreement with the data as compared to the case when symmetric nuclear matter $g$ matrices are used. These results provide evidence that the isospin-asymmetry in the $N N$ effective interaction yield non-negligible effects in nucleon scattering off isospin-asymmetric targets at beam energies below 65 MeV.
nucl-thPRC(2025)·1 citation
04
Harmonic chiral vibration in triaxial nuclei
R. Budaca · A. I. Budaca
The low spin states of chiral partner bands are described by means of harmonic oscillations of the total angular momentum vector. The validity of the adopted approximation is established in terms of triaxiality, quasiparticle alignments and the maximal total angular momentum. The spectral properties of the model are described in detail with experimental realizations presented for nuclei with large resultant quasiparticle alignments. The model provides a simple phenomenological way for the determination of the triaxial deformation from the experimental data and easily discernable observable signatures.
nucl-thPLB(2025)·1 citation
05
Coupled-channel contributions to the GDH sum rule from the Jülich-Bonn approach
Carolin Schneider🇩🇪 · Deborah Rönchen🇩🇪 · Christoph Hanhart🇩🇪 · Ulf-G. Meißner🇩🇪
We study the Gerasimov-Drell-Hearn (GDH) sum rule within a dynamical coupled-channel approach, the Jülich-Bonn model for light baryon resonances based on fits to an extensive data base of pion and photon induced data. Recently published photoproduction data for different observables with $π N$ and $η N$ final states are analyzed simultaneously with older data for the reactions $π N \to π N$ , $η N$ , $K Λ$ , $K Σ$ and $γ p \to π N$ , $η N$ , $K Λ$ , $K Σ$ . The impact of the new data on the resonance spectrum is investigated and the contribution of the individual channels to the GDH integral is determined.
nucl-thhep-phnucl-exEPJA(2025)·2 citations

Affiliations

first authorsco-authorsvia INSPIRE

Exploring Shell Evolution and N = 40 Magicity in Light-Mass Nuclei with Relativistc Mean Field Approach

Implication of neutron star observations to the origin of nucleon mass

Nonlocal {\it in-medium} effective interaction for nucleon scattering off isospin-asymmetric targets

Harmonic chiral vibration in triaxial nuclei

Coupled-channel contributions to the GDH sum rule from the Jülich-Bonn approach

Affiliations