Nuclear Theory·nucl-th

Monday·September 8, 2025

12 papers—3 primary·9 cross-listed

01
Nonlocal nucleon-nucleus optical potentials from chiral effective field theory
Laina M. Stahulak🇺🇸 · Jeremy W. Holt🇺🇸
We investigate the nonlocality in microscopic optical potentials derived from chiral effective field theory. For this purpose we employ the Perey-Buck ansatz, which connects the energy dependence of purely local optical potentials to a Gaussian spatial nonlocality. We find that the dominant source of energy dependence in the microscopic real optical potential indeed arises from spatial nonlocalities, while the energy dependence associated with the microscopic imaginary optical potential is a genuine time nonlocality. We present results for nonlocal nucleon-nucleus optical potentials for the calcium isotopic chain and study the dependence of the Woods-Saxon shape parameters on the isotopic number.
nucl-th0 citations
02
rho-Meson Nucleon Scattering Length from CLAS Threshold Photoproduction Measurements
Igor I. Strakovsky (GWU)🇺🇸 · Evgeny L. Isupov (MGU)🇷🇺 · Victor Mokeev (Jlab)🇺🇸 · Axel Schmidt (GWU)🇺🇸
Extending our study of the vector meson-nucleon scattering lengths (summary is given in Ref.~\cite{Strakovsky:2021vyk}), we are focusing on the $ρ$ -meson case using recent CLAS threshold data for the reaction $γ p \to ρp$ within the meson-baryon reaction model~\cite{CLAS:2018drk}. The total $σ_{t} (γ p \to ρp)$ and $σ_{t} (γ p \to ω p)$ cross sections are close below the momentum of the vector meson in CM $q = 0.2 GeV/c$ . Then the $ρp$ photoproduction cross section grows rapidly. Our result for $ρN$ scattering length is a factor of 4 smaller than the size of the hadron and the phenomenological determination of the $ω$ nucleon scattering length using threshold photoproduction cross sections. The observed difference between $ρN$ and $ω N$ scattering lengths is of interest for further understanding within the hadron structure theory.
nucl-thhep-exhep-phnucl-exPRD(2025)·5 citations
03
Ab initio study in the island of inversion within the two-major-shell valence space
X. C. Cao · C. F. Jiao
We present an \textit{ab initio} study of nuclear structure in the island of inversion around neutron number $N = 20$ , using multishell effective Hamiltonians derived from the valence-space in-medium similarity renormalization group approach combined with the quantum-number projected generator coordinate method. By progressively expanding the valence space from the \textit{sd} shell to the intermediate $s d f_{7/2} p_{3/2}$ space and, for the first time, to the full \textit{sdfp} shell, we investigate low-lying spectra, $E 2$ transition strengths, deformation properties, and neutron occupancies in even-even Ne, Mg, and Si isotopes around $N = 20$ . Our results show that enlarging the valence space significantly improves the description of quadrupole collectivity, yielding better agreement with experimental data for key observables such as the lowered $2^{+}$ energies and the enhanced $B (E 2; 0_{1}^{+} \to 2_{1}^{+})$ values. The analysis reveals the critical role of cross-shell multi-particle multi-hole excitations in breaking the $N = 20$ shell closure and establishing intruder-dominated ground states. It also demonstrates the ability of the VS-IMSRG+PGCM framework to capture both dynamical (short range) and static (long range) correlations across multiple major-oscillator shells.
nucl-thPLB(2025)·5 citations

Affiliations

first authorsco-authorsvia INSPIRE

Nonlocal nucleon-nucleus optical potentials from chiral effective field theory

rho-Meson Nucleon Scattering Length from CLAS Threshold Photoproduction Measurements

Ab initio study in the island of inversion within the two-major-shell valence space

Affiliations