Nuclear Theory·nucl-th

Wednesday·September 3, 2025

38 papers—18 primary·20 cross-listed

01
Impacts of isolated nucleon-nucleon correlations in relativistic $^{16}$ O+ $^{16}$ O collisions
Qi Liu🇨🇳 · Hadi Mehrabpour🇨🇳 · Bing-Nan Lu🇨🇳
Nucleon-nucleon interactions are fundamental to the nuclear forces operating within the nucleus and play a crucial role in shaping the initial conditions of relativistic ion collisions through two-nucleon correlations. In this paper, we introduce an innovative approach to explore these encoded nucleon-nucleon correlations within advanced \textit{ab-initio} models in the context of relativistic $^{16} O$ collisions. Our methodology successfully reproduces the structural properties of the nucleonic configurations generated by these models, as well as the distance correlations between the nucleon pairs, denoted as $C (Δ r)$ . By generating nucleon positions that align with authentic configurations and adhering to the constraints imposed by the probability distribution of relative two-nucleon distances, our goal is to better understand nucleon-nucleon interactions within \textit{ab-initio} frameworks.
nucl-thnucl-ex5 citations
02
Local spin polarization of $Λ$ hyperons and its interaction corrections
Cong Yi🇨🇳 · Shuo Fang🇨🇳 · Dong-Lin Wang🇨🇳 · Shi Pu🇨🇳
We have computed the second Fourier sine coefficient of the longitudinal spin polarization, $⟨ P_{z} sin 2 (ϕ_{p} - Ψ_{2})⟩$ , as a function of multiplicity or centrality in Au+Au collisions at $s_{N N} = 200$ GeV and in $p$ +Pb collisions at $s_{N N} = 8.16$ TeV using the CLVisc hydrodynamic framework. The numerical results successfully describe the data in Au+Au collisions. However, understanding the data in $p$ +Pb collisions remains a puzzle. Additionally, we have reported some recent developments in quantum kinetic theory and spin hydrodynamics.
nucl-thhep-phEPJ Web Conf.(2026)·2 citations
03
Hydrodynamic effects on spin polarization along the beam direction in Au+Au and p+Pb collisions
Cong Yi🇨🇳 · Xiang-Yu Wu🇨🇳 · Jie Zhu🇨🇳 · Shi Pu🇨🇳 · Guang-You Qin🇨🇳
We investigate hydrodynamic effects on the spin polarization of $Λ$ hyperons in Au+Au collisions at $s_{N N} = 200$ GeV and p+Pb collisions at $s_{N N} = 8.16$ TeV using the CLVisc hydrodynamic framework. We present numerical results for the second Fourier sine coefficient of the longitudinal spin polarization, $⟨ P_{z} sin 2 (ϕ_{p} - Ψ_{2})⟩$ , as a function of multiplicity (centrality) under three equilibrium scenarios: $Λ$ equilibrium, $s$ -quark equilibrium, and isothermal equilibrium. We highlight the respective roles of thermal vorticity and the thermal-shear tensor in generating $⟨ P_{z} sin 2 (ϕ_{p} - Ψ_{2})⟩$ across collision systems and scenarios.
nucl-thEPJ Web Conf.(2026)·2 citations
04
Testing hydrodynamic response to initial-state geometry in Pb+ $d^{↑}$ collisions
Heikki Mäntysaari🇫🇮 · Björn Schenke🇺🇸 · Chun Shen🇺🇸 · Wenbin Zhao🇺🇸
Deuterons with different polarization states have distinct shapes for their wavefunctions. This offers a unique opportunity to experimentally control the initial-state collision geometry with the polarization of the light-ion targets in relativistic heavy-ion experiments. We study the charged hadron elliptic flow coefficients with respect to the polarization angle of deuterons in Pb + polarized deuteron collisions using a hydrodynamics + hadronic transport model. Hydrodynamic response to initial-state geometry predicts a distinct sign of $v_{2}$ correlated with the deuteron's polarization states, providing a clean test case for elucidating the collective origin in small collision systems.
nucl-thhep-phnucl-exEPJ Web Conf.(2026)·0 citations
05
Event-by-event vortex rings in fixed-target p+Ar collisions
David Chinellato🇧🇷 · Michael Lisa🇺🇸 · Willian Serenone🇧🇷 · Chun Shen🇺🇸 · Jun Takahashi🇧🇷 · Giorgio Torrieri🇧🇷
We present event-by-event simulations for central asymmetric p+Ar collisions at $s_{NN} = 68$ GeV to investigate the formation and evolution of vortex-ring structures from the early-stage longitudinal flow velocity profile. Our predictions for their imprints on Lambda hyperon's polarization observables are complementary to those presented in Ref. [Phys.Rev.C 110 (2024) 5, 054908] and can be explored in the future fixed-target collisions at the Large Hadron Collider beauty (LHCb) experiment.
nucl-thhep-phnucl-exEPJ Web Conf.(2026)·0 citations
06
Simulating stochastic fluid dynamics
Chandrodoy Chattopadhyay🇺🇸 · Josh Ott🇺🇸 · Thomas Schaefer🇺🇸 · Vladimir Skokov🇺🇸
We present simulations of the real time dynamics of a fluid in the vicinity of a critical endpoint in the phase diagram. The relevant hydrodynamic theory is known as model H, and it is expected to describe the long-distance dynamics of QCD matter in the vicinity of a possible critical endpoint in the QCD phase diagram.
nucl-thEPJ Web Conf.(2026)·1 citation
07
In-plane transverse polarization in heavy-ion collisions
Anum Arslan🇨🇳 · Wen-Bo Dong🇨🇳 · Charles Gale🇨🇦 · Sangyong Jeon🇨🇦 · Qun Wang🇨🇳 · Xiang-Yu Wu🇨🇦
We give an analytical expression for the in-plane polarization $P^{x}$ , in heavy-ion collisions that has, to our knowledge, not been measured in heavy-ion collision experiments. We also carry out a numerical study of $P^{x}$ using a hydrodynamic model simulation as a cross-check for the analytical formula. It is found that if the temperature-gradient contribution is neglected the simulation result for $P^{x}$ qualitatively agrees with the analytical one. The prediction of $P^{x}$ can be tested in experiments and will contribute to provide a complete and consistent picture of spin phenomena in heavy-ion collisions.
nucl-thhep-phPRC(2026)·8 citations
08
Zemach radii and nuclear structure effects in hyperfine splitting of Lithium
Yilong Yang · Evgeny Epelbaum · Chen Ji · Pengwei Zhao
Nuclear structure effects are essential for describing hyperfine splittings from high-precision atomic spectroscopy measurements. These effects are often parametrized by the effective or elastic Zemach radii, with their difference poorly understood. We solve the longstanding discrepancy between the effective and elastic Zemach radii in $^{6}$ Li and $^{7}$ Li by performing \emph{ab initio} nuclear structure calculations that take into account nuclear polarizability effects. Our results demonstrate that nuclear polarizability effects, negligible in $^{7}$ Li, dominate in $^{6}$ Li and explain the observed significant deviation between the effective and elastic Zemach radii. Furthermore, we show that the ratios between the nuclear polarizability contributions in different nuclei are universal in the limit of closure and SU(4) symmetry of nuclear forces. In particular, the nuclear polarizability contribution in an odd-odd nucleus is enhanced by a factor of $μ_{p} / (μ_{p} + μ_{n}) ≃ 3$ , with $μ_{n, p}$ denoting the nucleon magnetic moments, compared to its odd- $A$ isotopes. The same mechanism also explains the Zemach radius deviations observed in $^{2}$ H and $^{3}$ He. These findings establish nuclear polarizability as the dominant source of isotope-dependent nuclear corrections to hyperfine splitting in light atoms.
nucl-thnucl-exphysics.atom-ph7 citations
09
The nuclear surface diffuseness effects on the alpha decay of heavy and super heavy nuclei
S. Mohammadi · R. Gharaei · S. A. Alavi
We select 300 different parent nuclei in the range Z from 64 to 106. The proximity potentials Zhang 2013 and Guo 2013 are employed to calculate the nuclear potential. The influence of the nuclear surface diffuseness is applied in the calculations of interaction potential between the emitted alpha particle and daughter nucleus through the reduced radius parameter. The systematic analysis of the radial behavior of interaction potential with and without the surface diffuseness effect reveals that these effects play decisive role in the calculation of nucleus-nucleus potential at the touching radius of the two interacting nuclei. We indicate that its influence decreases outside the touching configuration. In addition, our results reveal that the barrier penetration probability of the alpha particle through the barrier decreases by imposing the mentioned physical effects. It is worth noting that the calculated alpha-decay half-lives using the Zhang 2013 and Guo 2013 proximity potentials accompanied by the surface effects agree very well with the available experimental data. The theoretical halflives are calculated for 50 super-heavy nuclei using the modified forms of the Zhang 2013 and Guo 2013 models. The comparison with available experimental data and also with different empirical formulas demonstrates that the Guo 2013 model is suitable to deal with the alpha decay half-lives of SHN. Then the predictions of alpha decay half-lives for 65 SHN with Z from 120 to 126 are made by using Guo 2013 model with the surface effects. We found that there is a good agreement between our predicted half-lives and those obtained from semi-empirical formulas such as Royer and UDL.
nucl-thhep-phIJMPE(2025)·0 citations
10
Smooth band termination in $^{115}$ I
C. M. Petrache🇫🇷 · I. Ragnarsson🇸🇪
The cranked Nilsson-Strutinsky formalism is employed to investigate the band structure of $^{115}$ I from low to high spin. A set of eight rotational bands with well established spins and parities are analyzed. Five bands start at low spin and are assigned to the single-particle proton orbitals ( $d_{5/2}$ , $g_{7/2}$ ), $g_{9/2}$ , and $h_{11/2}$ , which are close to the Z=53 Fermi surface for a deformation of $ε_{2} = 0.2$ . The analysis of the observed level energies relative to a rotating liquid drop and spins versus $γ$ -ray energies allow to track the evolution of the configurations with increasing spin. It is of special interest that one band in the valence space is observed to a smooth termination at $I_{ma x} = 67/ 2^{+}$ .
nucl-thPRC(2025)·1 citation
11
Physics-Guided Neural Networks for Constructing Nucleon-Nucleon Inverse Potentials
Ayushi Awasthi · Anil Khachi · M.R. Ganesh Kumar · O.S.K.S. Sastri
We propose a physics-guided neural network (PGNN) framework for constructing nucleon-nucleon inverse potentials based on inverse scattering theory. The framework integrates the Phase Function Method (PFM) with a two-stage supervised multi-layer perceptron (MLP) model to extract the optimal parameters of the Malfliet-Tjon (MT) potential from sparse phase-shift data. A synthetic dataset of phase shifts is generated by solving the phase equation for angular momentum $ℓ$ = 0, using the fifth-order Runge-Kutta method, ensuring physically consistent training data. The first neural network predicts the attractive potential strength, $V ~_{A}$ , while the second estimates the repulsive strength, $V ~_{R}$ . The optimal range parameter, $μ$ , is obtained through error minimization between predicted and expected phase shifts, thereby enhancing both stability and accuracy compared to conventional inversion techniques. The PGNN framework is validated for the $^{1} S_{0}$ state of neutron-proton (n-p), proton-proton (p-p), and neutron-neutron (n-n) scattering at low energies. The constructed inverse potentials accurately reproduce the phase shifts reported in the literature and exhibit the expected features of nucleon-nucleon interactions, including a short-range repulsive core and an intermediate-range attractive well, with the n-p system showing the deepest potential minimum due to stronger binding. These results demonstrate that the proposed PGNN framework provides an efficient and accurate approach for constructing nuclear potentials, effectively bridging machine learning techniques with quantum scattering theory.
nucl-th1 citation
12
On $Ω_{3 c} N N$ and $Ω_{3 c} Ω_{3 c} N$ systems with HAL QCD potentials
Igor Filikhin🇺🇸 · Roman Ya. Kezerashvili🇺🇸 · Branislav Vlahovic🇺🇸
This study employs the Faddeev formalism in configuration space to investigate the $Ω_{3 c} N N$ cluster containing a triply charmed Omega baryon ( $Ω_{3 c}$ ). Using the recently reported HAL QCD $S$ -wave $Ω_{3 c} N$ potentials in the $^{3} S_{1}$ and $^{5} S_{2}$ channels, together with the MT-I--III nucleon--nucleon potential and neglecting the Coulomb force, we find no bound state for the $Ω_{3 c} n p$ system. We predict near-threshold resonances in the $J^{π} = 5/ 2^{+}$ (maximal total spin) and $J^{π} = 1/ 2^{+}$ (minimal total spin) states, with resonance energies of $1.1 MeV$ below and $0.0 MeV$ at the three-body breakup threshold, respectively, at Euclidean time $t / a = 16$ . A similar analysis of the $Ω_{3 c} Ω_{3 c} N$ system likewise reveals no bound states, though a possible resonance is indicated. The short-distance behavior of the HAL QCD $Ω_{3 c} N$ potential is also discussed.
nucl-thhep-latPRD(2025)·1 citation
13
Discrete and continuous spectrum of lightest hypernuclei
N. K. Kalzhigitov🇰🇿 · S. Amangeldinova🇰🇿 · V. O. Kurmangaliyeva🇰🇿 · V. S. Vasilevsky🇺🇦
We analyze the peculiarities of the interaction of the lambda hyperon with s-shell nuclei. The spectra of bound and scattering states are studied in the hypernuclei $_{Λ}^{2}$ H, $_{Λ}^{3}$ H, $_{Λ}^{4}$ H, $_{Λ}^{4}$ He and $_{Λ}^{5}$ He, which is considered as two-cluster configurations $p + Λ$ , $d$ + $Λ$ , $^{3}$ H+ $Λ$ , $^{3}$ He+ $Λ$ , $^{4}$ He+ $Λ$ , respectively. The explicit form of the folding potentials of such an interaction is presented in coordinate and oscillator representations, which help us to understand the structure of hypernuclei of interest. We compare energies of bound states, phase shifts of the elastic lambda hyperon, and neutron scattering from s-shell nuclei.
nucl-th1 citation
14
Axially Deformed Proton-Neutron Relativistic Quasiparticle Finite Amplitude Method for Charge-Exchange Transitions
Chen Chen · Zhengzheng Li · Yinu Zhang · Yifei Niu
The quasiparticle finite amplitude method (QFAM) is extended to describe charge-exchange transitions based on the relativistic Hartree-Bogoliubov model, adopting the point-coupling energy density functional DD-PC1 and a finite-range separable pairing force. After validation through comparison with relativistic quasiparticle random-phase approximation (QRPA) results in spherical nuclei, the deformation effects on isobaric analog resonances (IAR) and Gamow-Teller (GT) transitions in Zn isotopes are investigated. The GT strength exhibits significant fragmentation in deformed nuclei. The analysis of summed strengths and centroid energies in GT resonance region between the $K = 0$ and $K = 1$ components reveals that prolate configurations exhibit stronger $K = 1$ strength and lower $K = 1$ centroid energy, while oblate shapes show an opposite behavior, with stronger $K = 0$ strength and lower $K = 0$ energy. The effects of isoscalar pairing on GT strength distributions for different shape configurations are also examined.
nucl-thPRC(2025)·1 citation
15
Theory Summary
Hannah Elfner🇩🇪
This is the write-up of the summary talk on theory activities in the heavy-ion community as presented at Quark Matter 2025. It contains a (biased) selection of results from the parallel program of the conference. The progress is reported for three different areas: Bulk dynamics and initial state; jets, heavy flavor and electromagnetic probes and QCD phase diagram and observables. The idea is to convey the major achievements in the field and give a perspective for future directions.
nucl-thnucl-exEPJ Web Conf.(2026)·0 citations
16
Quantum simulations of Green's functions for small superfluid systems
Samuel Aychet-Claisse🇫🇷 · Denis Lacroix🇫🇷 · Vittorio Somà🇫🇷 · Jing Zhang🇫🇷
An end-to-end strategy for hybrid quantum-classical computations of Green's functions in many-body systems is presented and applied to the pairing model. The scheme makes explicit use of the spectral representation of the Green's function, which entails the calculation of the $N$ -body ground state as well as eigenstates and associated energies of the $(N \pm 1)$ -body neighbors. While the former is accessed via variational techniques, the latter are constructed by means of the quantum subspace expansion method. Different ansatzes for the ground-state wave function, originating from either classical or quantum approaches, are tested and compared to exact calculations. The resulting one-body Green's functions prove to be accurate approximations of the exact one for a large range of parameters, including across the normal-to-superfluid transition. As a byproduct, this approach yields a good description of odd systems provided that the starting even system is well reproduced by the variational ansatz.
nucl-thquant-phPRC(2026)·3 citations
17
Towards a topological data analysis for heavy-ion collisions
Federica Capellino🇩🇪 · Andrea Dubla🇩🇪 · Silvia Masciocchi🇩🇪 · Govert Nijs🇨🇭 · Daniel Spitz🇩🇪
The collective expansion of the quark-gluon plasma (QGP) created in heavy-ion collisions suggests that geometry-inspired approaches can be useful in extracting information about the QGP. In this work, a systematic study of observables based on topological data analysis is provided for simulations of heavy-ion collisions. Specifically, we implement persistent homology observables for metric-based complexes in the heavy-ion model Trajectum and provide predictions for Pb-Pb and O-O collisions, where the tunable model parameters are taken from a Bayesian analysis performed in Pb-Pb collisions. This, in particular, allows us to compute systematic uncertainties on our observables from the uncertainties in the model parameters. To bridge between new and already established observables, we build a dictionary linking the topological observables to traditional ones, such as particle multiplicities, momentum distributions, and the elliptic flow coefficient. While the persistent homology observables largely reflect known phenomenology and do not show enhanced sensitivity to the model's tunable parameters compared to conventional observables, this study demonstrates the viability and robustness of topological techniques in the context of heavy-ion physics. They may offer alternative perspectives and potential applications in heavy-ion physics.
nucl-thPRC(2025)·1 citation
18
Bayesian inference favors quark matter in neutron star interiors
Alexander Ayriyan🇵🇱 · Oleksii Ivanytskyi🇵🇱 · David Blaschke🇵🇱
We perform a physics-informed Bayesian analyses of the equation of state of hybrid neutron stars that incorporates color-flavor-locked quark matter modeled by a three-flavor non-local Nambu-Jona-Lasinio framework with vector repulsion and diquark pairing. Contrary to the model-agnostic Bayesian analyses our scheme allows for distinguishing between the scenarios of neutron stars with quark cores and without them. The used quark model realizes asymptotic conformality at high densities in accordance with perturbative QCD. The hadronic sector is described by the density-dependent relativistic functional DD2Y-T, which satisfies chiral effective field theory constraints and includes hyperonic degrees of freedom. We construct a large set of candidate hybrid EOSs by varying the vector and diquark couplings and apply a Maxwell construction for the quark-hadron phase transition. Observational constraints from recent NICER pulsar mass-radius measurements and tidal deformability from GW170817 are incorporated into the likelihood. Depending on whether the observational data from the black widow pulsar PSR J0952-0607 and the HESS J1731-347 object are included to the analysis or not, the posterior distribution favors vector and diquark couplings around $(η_{V}, η_{D}) ≃ (0.82, 0.40)$ or $(η_{V}, η_{D}) ≃ (0.64, 0.36)$ , respectively. This corresponds to equations of state that support two-solar-mass neutron stars with superconformal speed of sound and relatively low onset densities for deconfinement. Our findings indicate that the most probable hybrid EOSs are statistically preferred over the purely hadronic baseline. The corresponding probabilities of agreeing with the observational data differ by one or two orders of magnitude depending on the data set used. This suggests that quark cores may exist in all observed neutron stars.
nucl-thastro-ph.HEhep-phPRD(2026)·13 citations

Affiliations

first authorsco-authorsvia INSPIRE