Nuclear Theory·nucl-th

Thursday·November 6, 2025

12 papers—7 primary·5 cross-listed

01
[Submitted on 2 Nov 2025]
Investigation of the short-range correlation and its induced high-momentum tail by photon emission from intermediate energy heavy-ion reactions
Zhi Wang
The effect of high-momentum tail (HMT) in nucleon momentum distribution of neutron-rich nuclei has been investigated by employing proton-neutron bremsstrahlung photons in the reactions of $^{124}$ Sn + $^{124}$ Sn, $^{112}$ Sn + $^{112}$ Sn and $^{197}$ Au + $^{197}$ Au at intermediate energies based on the IBUU transport model. With the time evolution of photon multiplicity and the double differential probability of photon production, we show the emission of bremsstrahlung photons is sensitive to the high-momentum component in nucleon momentum distribution of neutron-rich nuclei, and the HMT can lead to an obvious increase of hard photon production from proton-neutron bremsstrahlung collisions. Finally, the ratio of double differential photon production probability is examined as possible probe of the HMT in nucleon momentum distribution of neutron-rich nuclei.
Subjects:
Nuclear Theory (nucl-th)
arXiv:
2511.02862 [pdf]
0 citations
02
[Submitted on 4 Nov 2025]
Large-Scale Calculations of $β$ -Decay Rates and Implications for $r$ -Process Nucleosynthesis
A. Ravlić · Y. Saito · W. Nazarewicz
Nuclear $β$ decay is a key element of the astrophysical rapid neutron capture process ( $r$ -process). In this paper, we present state-of-the-art global $β$ -decay calculations based on the quantified relativistic nuclear energy density functional theory and the deformed proton-neutron quasiparticle random-phase approximation. Our analysis considers contributions from allowed and first-forbidden transitions. We used two point-coupling functionals with carefully calibrated time-odd terms and isoscalar pairing strength. The new calculations display consistent results for both employed functionals, especially near the neutron drip line, suggesting slower $β$ decays past the $N = 126$ neutron shell closure than in commonly used $β$ -decay models. The new rates, along with the existing rates based on the latest non-relativistic calculations, are found to slow down the synthesis of heavy elements in the $r$ -process and significantly reduce the contribution of neutron-induced fission.
Comments:
Updated manuscript, merged Supplement and added link to the website
Subjects:
Nuclear Theory (nucl-th); High Energy Astrophysical Phenomena (astro-ph.HE); Nuclear Experiment (nucl-ex)
arXiv:
2511.02999 [pdf]
PRC(2026)·3 citations
03
[Submitted on 4 Nov 2025]
Constraining capture cross sections using proton inelastic scattering as a surrogate reaction
Aaina Thapa🇺🇸 · Jutta Escher🇺🇸 · Emanuel Chimanski🇺🇸 · Oliver Gorton🇺🇸 · Marc Dupuis🇫🇷 · Eun Jin In🇺🇸 · Shuya Ota🇺🇸 · Sophie Péru🇫🇷 · Walid Younes🇺🇸
The surrogate reaction method is an alternative to direct measurements of compound nuclear reaction cross sections. We introduce theory tools for extracting capture cross sections from experiments that use proton inelastic scattering as a surrogate reaction mechanism. This makes it possible to constrain compound nucleus decay models which are typically the largest source of uncertainty in capture cross section calculations. This letter describes the theory developments that were used to simultaneously infer $^{89}$ Y $(p, γ)$ and $^{89}$ Zr $(n, γ)$ cross sections from $^{90}$ Zr $(p, p^{'} γ)$ surrogate measurements.
Comments:
5 pages, 4 figures
Subjects:
Nuclear Theory (nucl-th); Nuclear Experiment (nucl-ex)
arXiv:
2511.03071 [pdf]
PLB(2026)·2 citations
04
[Submitted on 5 Nov 2025]
Centroids of nuclear shell-model Hamiltonians, with optimization of energy-based truncation schemes
Calvin W. Johnson · Austin Keller
The configuration-interaction shell model is an effective and widely-used approach to the nuclear many-body problem, whose main drawback is the exponential growth of the basis dimension. An useful way to character nuclear shell-model Hamiltonians is through traces, including traces in subspaces defined by orbital occupations. Such traces, or energy centroids, can be easily and efficiently computed through the monopole components of the nuclear interaction, that is, terms that go like $n_{a} n_{b}$ where $n_{a}$ is the occupation of the single-particle orbital labeled by $a$ . These calculations can be carried out very quickly for both empirical (valence space) and no-core shell model spaces and interactions. In fact, they can be carried out so fast, one can use this to optimize an efficient, if approximate, many-body truncation scheme used in available nuclear shell-model codes such as BIGSTICK. To carry out both the traces and the optimization, we present the TRACER code, written in Fortran90 and described and available here. We give example results as well as discuss performance.
Comments:
12 pages, 3 figures; code available at github.com/cwjsdsu/tracer
Subjects:
Nuclear Theory (nucl-th)
arXiv:
2511.03161 [pdf]
1 citation
05
[Submitted on 5 Nov 2025]
Impact of QCD Energy Evolution on Observables in Heavy-Ion Collisions
Heikki Mäntysaari🇫🇮 · Björn Schenke🇺🇸 · Chun Shen🇺🇸 · Wenbin Zhao🇨🇳
We study how the inclusion of energy dependence as dictated by quantum chromodynamic (QCD) small- $x$ evolution equations affects key observables in ultra-relativistic heavy-ion collisions. Specifically, we incorporate JIMWLK evolution into the IP-Glasma framework, which serves as the initial condition for a simulation pipeline that includes viscous relativistic hydrodynamics and a hadronic afterburner. This approach enables a consistent modeling of highly energetic nuclei across varying Bjorken- $x$ values, which are relevant for different collision energies and rapidity regions. In comparison to the standard IP-Glasma setup without small- $x$ evolution, we observe pronounced changes in particle multiplicities and spectral distributions, especially in smaller systems and at the highest available energies. We further explore effects on anisotropic flow observables and correlations between mean transverse momentum and elliptic flow. Our findings underscore the critical role of nonlinear QCD evolution in accurately modeling the early stages of heavy-ion collisions, as well as its implications for extracting transport properties of the quark-gluon plasma.
Comments:
Update to the version that published in the Phys.Rev.C 113 (2026) 3, 034914
Subjects:
Nuclear Theory (nucl-th); High Energy Physics — Phenomenology (hep-ph); Nuclear Experiment (nucl-ex)
arXiv:
2511.03588 [pdf]
PRC(2026)·2 citations
06
[Submitted on 5 Nov 2025]
Violation of the elliptic flow scaling of $f_{0} (980)$ in p-Pb collisions at the LHC
Yili Wang🇨🇳 · Wenbin Zhao🇺🇸 · Che Ming Ko🇺🇸 · Feng-Kun Guo🇨🇳 · Ju-Jun Xie🇨🇳 · Huichao Song🇨🇳
We investigate the production and elliptic flow of the $f_{0} (980)$ in high-multiplicity p-Pb collisions at $s_{N N} = 5.02$ TeV using a hadronic coalescence model with the $K$ and $K ˉ$ phase-space distributions provided by the Hydro-Coal-Frag hybrid model. Our results, which agree with the ALICE and CMS measurements, support the $K K ˉ$ molecular interpretation of the $f_{0} (980)$ structure and show, however, a breakdown of the simple number-of-constituent (NC) scaling of its elliptic flow. The latter is in contrast to the deuteron elliptic flow, which exhibits a significantly better NC scaling when the same coalescence width parameter is used.
Subjects:
Nuclear Theory (nucl-th); Nuclear Experiment (nucl-ex)
arXiv:
2511.03637 [pdf]
EPJ Web Conf.(2026)·1 citation
07
[Submitted on 5 Nov 2025]
Probing the structure of $f_{0} (980)$ from the elliptic flow in p-Pb collisions at the LHC
Yili Wang🇨🇳 · Wenbin Zhao🇨🇳 · Che Ming Ko🇺🇸 · Fengkun Guo🇨🇳 · Ju-Jun Xie🇨🇳 · Huichao Song🇨🇳
The $f_{0} (980)$ is a light scalar meson whose internal structure remains under debate and investigation. Assuming that the $f_{0} (980)$ is a $K K ˉ$ molecule that can only survive at the kinetic freeze-out of the evolving bulk matter, we implement the coalescence model to study its transverse momentum ( $p_{T}$ ) spectra and elliptic flow ( $v_{2}$ ) in high-multiplicity p-Pb collisions at $s_{N N} = 5.02$ TeV. Using the well-tuned kaon phase-space distributions from the Hydro-Coal-Frag model, our $K K ˉ$ coalescence calculations with reasonable values for the $f_{0} (980)$ radius successfully reproduce the elliptic flow measured by CMS over the range $0 < p_{T} < 12$ GeV and also agree with the $p_{T}$ -spectra from ALICE. These results in heavy ion collisions are consistent with the $K K ˉ$ molecular picture of the $f_{0} (980)$ . We also find that the number-of-constituent scaling of $v_{2}$ for the $f_{0} (980)$ is violated in p-Pb collisions at the LHC because most $f_{0} (980)$ are produced from the coalescence of kaons that have different momenta. Our study demonstrates the necessity of realistic coalescence model calculations and also explains why the CMS interpretation of the $f_{0} (980)$ as an ordinary $q q ˉ$ meson is no longer valid by interpreting the measured $v_{2}$ with a simple scaling formula based on the assumption of equal momentum coalescence. The investigation also provides a novel way to explore the internal structure of light exotic hadrons that can be abundantly produced in relativistic heavy and/or light ion collisions.
Subjects:
Nuclear Theory (nucl-th); Nuclear Experiment (nucl-ex)
arXiv:
2511.03638 [pdf]
PLB(2026)·0 citations

Affiliations

first authorsco-authorsvia INSPIRE

Investigation of the short-range correlation and its induced high-momentum tail by photon emission from intermediate energy heavy-ion reactions

Large-Scale Calculations of β-Decay Rates and Implications for r-Process Nucleosynthesis

Constraining capture cross sections using proton inelastic scattering as a surrogate reaction

Centroids of nuclear shell-model Hamiltonians, with optimization of energy-based truncation schemes

Impact of QCD Energy Evolution on Observables in Heavy-Ion Collisions

Violation of the elliptic flow scaling of f0​(980) in p-Pb collisions at the LHC

Probing the structure of f0​(980) from the elliptic flow in p-Pb collisions at the LHC

Affiliations

Large-Scale Calculations of $β$ -Decay Rates and Implications for $r$ -Process Nucleosynthesis

Violation of the elliptic flow scaling of $f_{0} (980)$ in p-Pb collisions at the LHC

Probing the structure of $f_{0} (980)$ from the elliptic flow in p-Pb collisions at the LHC