Nuclear Theory·nucl-th

Thursday·February 27, 2025

16 papers—6 primary·10 cross-listed

01
[Submitted on 26 Feb 2025]
Quantum Monte Carlo Calculations of neutron- $α$ Scattering via an Integral Relation
Abraham R. Flores · Kenneth M. Nollett · Maria Piarulli
Nuclear physics seeks to describe both bound and unbound states within a unified predictive framework. While coordinate-space Quantum Monte Carlo (QMC) methods have successfully computed bound states for systems with $A \leq 12$ , their application to unbound states remains limited. In this work, we extend the QMC approach to enable a broader range of unbound-state calculations. Our method infers long-range amplitudes in the wave function from integrals over the short-range interaction region. By evaluating these integrals using Green's Function Monte Carlo wave functions with the Argonne $v_{18}$ potential, we accurately reproduce existing results for neutron-alpha scattering. This approach provides a systematic pathway for studying more complex nuclear systems, including coupled-channel scattering and the effects of three-nucleon forces. It serves as a powerful tool for advancing $ab initio$ calculations in nuclear reactions, paving the way for a unified framework that consistently describes both bound and scattering states within a single theoretical approach.
Comments:
38 pages, 9 figures
Subjects:
Nuclear Theory (nucl-th)
arXiv:
2502.18718 [pdf]
PRC(2025)·7 citations
02
[Submitted on 26 Feb 2025]
Ab Initio Calculations of the Carbon and Oxygen Isotopes: Energies, Correlations, and Superfluid Pairing
Young-Ho Song · Myungkuk Kim · Youngman Kim · Kihyeon Cho · Serdar Elhatisari · Dean Lee · Yuan-Zhuo Ma · Ulf-G. Meißner
We perform \textit{ab initio} nuclear lattice calculations of the neutron-rich carbon and oxygen isotopes using high-fidelity chiral interactions. We find good agreement with the observed binding energies and compute correlations associated with each two-nucleon interaction channel. For the isospin $T = 1$ channels, we show that the dependence on $T_{z}$ provides a measure of the correlations among the extra neutrons in the neutron-rich nuclei. For the spin-singlet S-wave channel, we observe that any paired neutron interacts with the nuclear core as well as its neutron pair partner, while any unpaired neutron interacts primarily with only the nuclear core. For the other partial waves, the correlations among the extra neutrons grow more slowly and smoothly with the number of neutrons. These general patterns are observed in both the carbon and oxygen isotopes and may be universal features that appear in many neutron-rich nuclei.
Comments:
25 pages, 18 figures, to be published in Phyiscs Letters B
Subjects:
Nuclear Theory (nucl-th); High Energy Physics — Phenomenology (hep-ph); Nuclear Experiment (nucl-ex)
arXiv:
2502.18722 [pdf]
PLB(2026)·8 citations
03
[Submitted on 26 Feb 2025]
Forbidden non-unique $β^{-}$ transitions and $g_{A}$ -sensitive electron spectral-shapes
Archana Saxena · Praveen C. Srivastava
In the present work, we have done a systematic study of beta decay properties such as electron spectral-shapes, shape factors, and log $f t$ values for the higher forbidden non-unique $β^{-}$ transitions in the mass region A=85-123. We have performed the nuclear shell model (SM) calculations to explore the sensitivity of the electron spectral-shapes for different axial-vector coupling constants $g_{A} = 0.8 - 1.27$ . The effective interactions GWBXG, G-matrix, SNET and SN100PN are used for different model spaces. In the present work, we have computed the electron spectral-shapes of $^{85}$ Br, $^{87}$ Rb, $^{93}$ Zr, $^{97}$ Zr, $^{101}$ Mo, $^{115}$ Cd, $^{117}$ Cd, $^{119}$ In, $^{123}$ Sn and $^{135}$ Cs by constraining the small relativistic nuclear matrix element from conserved vector-current hypothesis (CVC). We have found that the electron spectral-shapes are strongly dependent on $g_{A}$ except the second forbidden non-unique $β^{-}$ transition $^{93}$ Zr.
Comments:
12 pages, 4 figures, and 3 tables; Physical Review C (2025)
Subjects:
Nuclear Theory (nucl-th); Nuclear Experiment (nucl-ex)
arXiv:
2502.18815 [pdf]
PRC(2025)·0 citations
04
[Submitted on 26 Feb 2025]
Deuteron-Deuteron Interaction and Correlation Function
Duo-Lun Ge🇨🇳 · Zhi-Wei Liu🇨🇳 · Jun-Xu Lu🇨🇳 · Li-Sheng Geng🇨🇳
The interaction between deuterons ( $d$ - $d$ ) is pivotal for understanding the characteristics of certain light nuclei from the perspective of the deuteron cluster and achieving a precise reproduction of $d$ - $d$ fusion cross sections. In this work, we construct a new set of elastic $d$ - $d$ interactions by fitting the phase shifts using potentials parameterized in a Woods-Saxon shape. Then, the correlation functions are calculated with the obtained potential and compared with the recent measurements by the STAR collaboration. We find that the $d$ - $d$ phase shifts and the correlation functions are internally consistent, confirming that correlation functions can provide cross-check for the $d$ - $d$ interaction. In addition, both the $^{1} S_{0}$ bound state and the repulsive $^{5} S_{2}$ interaction contribute to the observed suppression in the measured correlation function. Moreover, we demonstrate that the $P$ -wave contribution of the correlation functions cannot be neglected, especially in determining the source size.
Comments:
7 pages, 4 figures, 1 table; accepted for publication in Physical Review C
Subjects:
Nuclear Theory (nucl-th)
arXiv:
2502.18872 [pdf]
PRC(2025)·13 citations
05
[Submitted on 26 Feb 2025]
Rescattering effects on spin-interference for $ρ^{0}$ photoproduction in heavy-ion collisions
Yusong Wang🇨🇳 · Xinbai Li🇨🇳 · Ziyang Li🇨🇳 · Zebo Tang🇨🇳 · Xin Wu🇨🇳 · Wangmei Zha🇨🇳
Recent measurements by various experiments in ultra-peripheral collisions have observed spin-interference in $ρ^{0}$ photoproduction, marking a breakthrough in Fermi-scale quantum interference experiments. Building on this, STAR extended the measurement to hadronic heavy-ion collisions, where significant rescattering effects on $ρ^{0}$ mesons were expected. In this study, we investigate how these rescattering effects influence the measurement of spin-interference. By embedding $ρ^{0}$ mesons produced via photoproduction, modeled by the Vector Meson Dominance model, into the Ultrarelativistic Quantum Molecular Dynamics framework, we estimate the impact on the $cos 2 ϕ$ and $cos 4 ϕ$ modulations, where $ϕ$ is the angle between $ρ^{0}$ and one of the daughters' ( $π^{\pm}$ ) transverse momentum. The results indicate a significant suppression of the $cos 2 ϕ$ modulation, while the $cos 4 ϕ$ modulation remains largely unaffected, which provides insight for understanding the difference due to rescattering effects between experimental measurements and theoretical predictions for $ρ^{0}$ photoproduction in heavy-ion collisions.
Comments:
9 pages, 11 figures
Subjects:
Nuclear Theory (nucl-th); High Energy Physics — Experiment (hep-ex); Nuclear Experiment (nucl-ex)
arXiv:
2502.19065 [pdf]
PRC(2025)·0 citations
06
[Submitted on 26 Feb 2025]
Firewall boundaries and mixed phases of rotating quark matter in linear sigma model
Sergio Morales-Tejera🇷🇴 · Victor E. Ambruş🇷🇴 · Maxim N. Chernodub🇷🇴
A rigidly-rotating body in unbounded space is usually considered a pathological system since it leads to faster-than-light velocities and associated breaches of causality. However, numerical results on chiral symmetry breaking in rotating plasmas of interacting fermions reveal surprisingly close correspondence in predictions between the rigorous bounded and formal unbounded approaches. To provide insight into this correlation, we consider the linear sigma model coupled to quarks, undergoing rigid rotation in unbounded Minkowski space-time. Within the mean-field approach, we adopt three consecutive levels of approximation to the ground state of the system that feature uniform (model 1), weakly inhomogeneous (model 2) and fully inhomogeneous (model 3) condensates. Models 1 and 2 that do not take into account spatial gradients of the condensate show agreement with the Tolman-Ehrenfest law. Model 3 exhibits a deviation from the Tolman-Ehrenfest prediction due to the appearance of a new energy scale set by the inhomogeneity of the ground state. Its boundary conditions are fixed by imposing regularity at the rotation axis and by demanding the global minimization of the grand potential. We dub the latter as ``firewall boundary conditions,'' translating into the requirement of vanishing condensate on the light cylinder, which follows from the fact that the system state formally diverges at the light cylinder. In all models, we present the phase diagram of the system and point out that in models 2 and 3, the system resides either in a chirally-restored phase, or in a mixed phase that possesses spatially-separated chirally-restored and chirally-broken phases. Finally, we discuss the properties of the system under inhomogeneous rotation using the relativistic version of the Rankine vortex model.
Comments:
24 pages, 23 figures
Subjects:
Nuclear Theory (nucl-th); High Energy Physics — Theory (hep-th)
arXiv:
2502.19087 [pdf]
PRD(2025)·9 citations

Affiliations

first authorsco-authorsvia INSPIRE

Quantum Monte Carlo Calculations of neutron-α Scattering via an Integral Relation

Ab Initio Calculations of the Carbon and Oxygen Isotopes: Energies, Correlations, and Superfluid Pairing

Forbidden non-unique β− transitions and gA​-sensitive electron spectral-shapes

Deuteron-Deuteron Interaction and Correlation Function

Rescattering effects on spin-interference for ρ0 photoproduction in heavy-ion collisions

Firewall boundaries and mixed phases of rotating quark matter in linear sigma model

Affiliations

Quantum Monte Carlo Calculations of neutron- $α$ Scattering via an Integral Relation

Forbidden non-unique $β^{-}$ transitions and $g_{A}$ -sensitive electron spectral-shapes

Rescattering effects on spin-interference for $ρ^{0}$ photoproduction in heavy-ion collisions