Nuclear Theory·nucl-th

Wednesday·November 12, 2025

11 papers—3 primary·8 cross-listed

01
[Submitted on 11 Nov 2025]
What happens in hydrodynamic simulations of heavy-ion collisions when causality is violated?
Lorenzo Gavassino🇺🇸 · Henry Hirvonen🇺🇸 · Jean-Francois Paquet🇺🇸 · Mayank Singh🇺🇸 · Gabriel Soares Rocha🇺🇸
We summarize our recent investigations on how causality violations in Israel-Stewart-type relativistic viscous hydrodynamic simulations can give rise to both analytical and numerical instabilities. The classification of spacetime regions into causal and stable ("good"), acausal but stable ("bad"), and acausal and unstable ("ugly") is reviewed. We compare the predictions of the MUSIC hydrodynamic solver with an analytical solution, and demonstrate how the acausality-driven instabilities develop in a simple one-dimensional scenario.
Comments:
Proceedings of Quark Matter 2025 (accepted version), see https://indico.cern.ch/event/1334113/papers/6289778/
Subjects:
Nuclear Theory (nucl-th); High Energy Physics — Theory (hep-th)
arXiv:
2511.07946 [pdf]
EPJ Web Conf.(2026)·0 citations
02
[Submitted on 11 Nov 2025]
$α$ -decay half-lives and $α$ -cluster preformation factors of nuclei around $N = Z$ line
Jing Li · Shan He · Yueqing Li · Weiwei Wang · Yanzhao Wang · Jianzhong Gu
In this work, a microscopic effective nucleon-nucleon interaction based on the Dirac-Brueckner-Hartree-Fock $G$ matrix starting from a bare nucleon-nucleon interaction is used to explore the $α$ -decay half-lives of the nuclei near $N = Z$ line. Specifically, the $α$ -nucleus potential is constructed by doubly folding the effective nucleon-nucleon interaction with respect to the density distributions of both the $α$ -cluster and daughter nucleus. Moreover, the $α$ -cluster preformation factor is extracted by a cluster formation model. It is shown that the calculated half-lives can reproduce the experimental data well. Then, the $α$ -decay half-lives that are experimentally unavailable for the nuclei around $N = Z$ are predicted, which are helpful for searching for the new candidates of $α$ -decay in future experiments. In addition, by analyzing the proton-neutron correlation energy and two protons-two neutrons correlation energy of $Z = 52$ and $Z = 54$ isotopes, the $α$ -cluster preformation factor evolution with $N$ is explained. Furthermore, it is found that the two protons-two neutrons interaction plays more important role in $α$ -cluster preformation than the proton-neutron interaction. Meanwhile, proton-neutron interaction results in the odd-even effect of the $α$ -cluster preformation factor.
Subjects:
Nuclear Theory (nucl-th)
arXiv:
2511.08051 [pdf]
0 citations
03
[Submitted on 11 Nov 2025]
Finite-range pairing in nuclear density functional theory
Sudhanva Lalit · Paul-Gerhard Reinhard · Kyle Godbey · Witold Nazarewicz
Pairing correlations are ubiquitous in low-energy states of atomic nuclei. To incorporate them within nuclear density functional theory, often used for global computations of nuclear properties, pairing functionals that generate nucleonic pair densities and pairing fields are introduced. Many pairing functionals currently used can be traced back to zero-range nucleon-nucleon interactions. Unfortunately, such functionals are plagued by deficiencies that become apparent in large model spaces that contain unbound single-particle (continuum) states. In particular, the underlying computational schemes diverge as the single-particle space increases, and the results depend on how marginally occupied states are incorporated. These problems become more pronounced for pairing functionals that contain gradient-density dependence, such as in the Fayans functional. To remedy this, finite-range pairing functionals are introduced. In this study, this is done by folding the pair density with Gaussians. We show that a folding radius of about 1\,fm offers the best compromise between quality and stability, and substantially reduces the pathological behavior in different numerical applications.
Comments:
12 pages, 10 figures
Subjects:
Nuclear Theory (nucl-th)
arXiv:
2511.08366 [pdf]
PRC(2026)·3 citations

Affiliations

first authorsco-authorsvia INSPIRE

What happens in hydrodynamic simulations of heavy-ion collisions when causality is violated?

α-decay half-lives and α-cluster preformation factors of nuclei around N=Z line

Finite-range pairing in nuclear density functional theory

Affiliations

$α$ -decay half-lives and $α$ -cluster preformation factors of nuclei around $N = Z$ line