Nuclear Theory·nucl-th

Wednesday·April 23, 2025

10 papers—6 primary·4 cross-listed

01
Angular structure of many-body correlations in atomic nuclei: From nuclear deformations to diffractive vector meson production in $γ A$ collisions
Jean-Paul Blaizot🇫🇷 · Giuliano Giacalone🇫🇷
There is growing evidence that high-energy scattering processes involving nuclei can offer unique insights into the many-body correlations present in nuclear ground states, in particular those of deformed nuclei. These processes involve, for instance, the collective anisotropic flows in heavy-ion collisions, or the diffractive production of vector mesons in photo-nuclear ( $γ A$ ) interactions. In this paper, we use a classical approximation and simple analytical models in order to exhibit characteristic and universal features of ground-state correlation functions that result from the presence of a deformed intrinsic state. In the case of a small axial quadrupole deformation, we show that the random rotation of the intrinsic density of the nucleus leads to a specific quadrupole modulation of the lab-frame two-body density as a function of the relative azimuthal angle. As a phenomenological, albeit academic application, we analyze the diffractive production of vector mesons in high-energy $γ +^{8}$ Be collisions. This demonstrates with the simplest deformed nucleus how the two-body correlations impact the $∣ t ∣$ dependence of the incoherent cross sections.
nucl-thhep-exhep-phnucl-exEPJA(2025)·14 citations
02
Study of neutron-deficient nucleus 224Np and its {\alpha} decay by particle-number-conserving method in the framework of deformed shell model
Xiao-Tao He · Kun Huang · T. M. Shneidman · N. V. Antonenko · Jun Zhang · Hong-qiang You
The particle-number-conserving (PNC) method in the framework of the deformed shell model (DSM) is employed to study the properties of the newly discovered short-lived neutron-deficient nucleus 224Np and its {\alpha}-decay. The calculated energy of {\alpha}-particle lies within 300 keV of the experimental data. This is the first application of the PNC method to the region of neutron-deficient nuclei. This work provides the first attempt to combine the microscopic PNC theory with empirical formulas to study the nuclear {\alpha} decay. The configurations of ground states are assigned as {\pi}5/2-[523]{\otimes}{\nu}5/2+[633] for 224Np, {\pi}1/2-[530]{\otimes}{\nu}3/2+[642] for 220Pa, {\pi}3/2+[651]{\otimes}{\nu}1/2-[501] for 216Ac, and {\pi}7/2-[514]{\otimes}{\nu}3/2-[501] for 212Fr. The absence of the Z = 92 subshell closure in 224Np is explained by analyzing the proton single-particle levels. Low-lying excited statesare predicted for nuclei along the {\alpha}-decay chain by the PNC method. Based on the PNC predicted {\alpha}-decay energy and the assigned configurations, the {\alpha}-decay half-lives are calculated by the empirical formulas, in which the angular momentum taken away by the {\alpha} particle is taken into account. The angular momentum have an important effect on the {\alpha}-decay half-life. The errors of the empirical formulas calculation are in two orders of magnitude with the experimental data.
nucl-thPRC(2025)·2 citations
03
Charge dependent nucleon-nucleon potentials in covariant chiral effective field theory
Yang Xiao🇨🇳 · Jun-Xu Lu🇨🇳 · Chun-Yan Song🇨🇳 · Li-Sheng Geng🇨🇳
The charge-dependent nucleon-nucleon ( $N N$ ) interaction plays a crucial role in understanding the nuclear structure and reaction problems. In this work, we explore the charge-dependent $N N$ interaction in covariant chiral effective field theory. By incorporating the isospin-breaking contributions, we derive the charge-dependent covariant chiral $N N$ potential up to next-to-next-to leading order (NNLO). The calculated $n p$ and $pp$ phase shifts are in satisfactory agreement with the PWA93 partial wave analysis. Our results contribute to a deeper understanding of isospin-breaking effects in nuclear forces and provide a solid foundation for future studies of nuclear structure and reactions within the covariant framework.
nucl-thPRC(2026)·3 citations
04
Electroweak form factors of baryons in dense nuclear matter
G. Ramalho🇰🇷 · K. Tsushima🇧🇷 · Myung-Ki Cheoun🇰🇷
There is evidence that the properties of hadrons are modified in a nuclear medium. Information about the medium modifications of the internal structure of hadrons is fundamental for the study of dense nuclear matter and high-energy processes, including heavy-ion and nucleus--nucleus collisions. At the moment, however, empirical information about medium modifications of hadrons is limited; therefore, theoretical studies are essential for progress in the field. In the present work, we review theoretical studies of the electromagnetic and axial form factors of octet baryons in symmetric nuclear matter. The calculations are based on a model that takes into account the degrees of freedom revealed in experimental studies of low and intermediate square transfer momentum $q^{2} = - Q^{2}$ : valence quarks and meson cloud excitations of baryon cores. The formalism combines a covariant constituent quark model, developed for a free space (vacuum) with the quark--meson coupling model for extension to the nuclear medium. We conclude that the nuclear medium modifies the baryon properties differently according to the flavor content of the baryons and the medium density. The effects of the medium increase with density and are stronger (quenched or enhanced) for light baryons than for heavy baryons. In particular, the in-medium neutrino--nucleon and antineutrino--nucleon cross-sections are reduced compared to the values in free space. The proposed formalism can be extended to densities above the normal nuclear density and applied to neutrino--hyperon and antineutrino--hyperon scattering in dense nuclear matter.
nucl-thhep-exhep-lathep-ph+1Symmetry(2025)·8 citations
05
Compatibility of recent $Ξ$ -nuclear bound state signals
E. Friedman🇮🇱 · A. Gal🇮🇱
J-PARC E05 reported recently a hint of a $Ξ^{-} -^{11} B$ nuclear state in the $^{12} C (K^{-}, K^{+})_{Ξ}^{12} Be$ spectrum, bound by $B_{Ξ^{-}} = 8.9 \pm 1.4_{- 3.1}^{+ 3.8}$ MeV. Using a density-dependent $Ξ$ -nuclear optical potential $V_{opt}^{Ξ} (ρ)$ we explore to what extent a $Ξ_{1 s}^{-}$ assignment of this nuclear state is compatible with $Ξ_{1 s}^{-}$ and $Ξ_{1 p}^{-}$ nuclear-state interpretations of $Ξ^{-}$ capture events in light emulsion-nuclei experiments. We find that the only acceptable $Ξ_{1 s}^{-}$ assignment at present, barring an abnormally strong repulsive $ρ^{2}$ component of $V_{opt}^{Ξ} (ρ)$ , is that for the $Ξ^{-} -^{11} B$ signal. This finding supports reassigning $Ξ^{-}$ capture events in $^{14}$ N, originally assigned as $Ξ_{1 s}^{-} -^{14} N$ nuclear states, to $Ξ_{1 p}^{0} -^{14} C$ nuclear states. The depth of $V_{opt}^{Ξ} (ρ)$ at nuclear-matter density $ρ_{0} = 0.17$ fm $^{- 3}$ is then $- V_{opt}^{Ξ} (ρ_{0}) \sim 21$ MeV.
nucl-thhep-phnucl-exPLB(2025)·7 citations
06
Shear Viscosity and Electrical Conductivity of Rotating Nuclear Medium in Hadron Resonance Gas and Nambu-Jona Lasinio Models
Ashutosh Dwibedi · Dani Rose J Marattukalam · Nandita Padhan · Dushmanta Sahu · Jayanta Dey · Kangkan Goswami · Arghya Chatterjee · Sabyasachi Ghosh · Raghunath Sahoo
Motivated by recent observations of spin polarization and alignment in heavy-ion collisions, we study the impact of rotation on the transport properties of strongly interacting matter within kinetic theory in the relaxation time approximation. Our analysis focuses on the anisotropic shear viscosity--parallel ( $η_{∥}$ ), perpendicular ( $η_{⊥}$ ), and Hall ( $η_{\times}$ )--and electrical conductivity-- $σ_{∥}$ , $σ_{⊥}$ , and $σ_{\times}$ --induced by the Coriolis force in a rotating medium. We employ two approaches: a combined quark-gluon plasma--hadron resonance gas (QGP--HRG) framework and a two-flavor Nambu--Jona-Lasinio (NJL) model. In the QGP--HRG description, noninteracting HRG (massless partonic) degrees of freedom are used below (above) the transition temperature. In the NJL model, rotation enters through spinorial connections in the Lagrangian, and the constituent quark masses are obtained over the full temperature range. Rotation suppresses the chiral condensate and slightly enhances the transport coefficients for phenomenologically relevant angular velocities. Assuming a temperature-dependent angular velocity consistent with standard cooling, we find that $η_{∣∣, ⊥, \times} / s$ and $σ_{⊥, \times} / T$ exhibit a valley-like temperature dependence, with reduced magnitudes compared to the isotropic $η / s$ and $σ / T$ obtained without rotation. At zero net baryon density, rotation generates a sizable nondissipative Hall-like conductivity, unlike the case with magnetic fields where baryon and antibaryon contributions cancel.
nucl-thhep-thPhys. Rev. C 113, 044903 (2026)

Affiliations

first authorsco-authorsvia INSPIRE

Angular structure of many-body correlations in atomic nuclei: From nuclear deformations to diffractive vector meson production in γA collisions

Study of neutron-deficient nucleus 224Np and its {\alpha} decay by particle-number-conserving method in the framework of deformed shell model

Charge dependent nucleon-nucleon potentials in covariant chiral effective field theory

Electroweak form factors of baryons in dense nuclear matter

Compatibility of recent Ξ-nuclear bound state signals

Shear Viscosity and Electrical Conductivity of Rotating Nuclear Medium in Hadron Resonance Gas and Nambu-Jona Lasinio Models

Affiliations

Angular structure of many-body correlations in atomic nuclei: From nuclear deformations to diffractive vector meson production in $γ A$ collisions

Compatibility of recent $Ξ$ -nuclear bound state signals