Nuclear Theory·nucl-th

Tuesday·January 28, 2025

19 papers—13 primary·6 cross-listed

01
[Submitted on 24 Jan 2025]
Signature of the $α$ -clustering structure of Light Nuclei in Relativistic Nuclear Collisions
Zhiyong Lu🇨🇳 · Mingrui Zhao🇨🇳 · Emil Gorm Dahlbæk Nielsen🇩🇰 · Xiaomei Li🇨🇳 · You Zhou🇩🇰
The "imaging-by-smashing" technique has been developed recently in relativistic nuclear collisions. By smashing heavy nuclei at RHIC and the LHC and analyzing the anisotropic expansion (flow) of the final state produced particles, unique information on the structure of the collided nuclei has been obtained. Existing efforts primarily focus on the colliding mode of heavy nuclei collisions. In contrast, nuclear structure studies with collisions of light nuclei and the fixed target mode, despite their significant impact and broad interest, have not been thoroughly explored. In this Letter, we investigate the $α$ -clustering signature of $^{20}$ Ne and $^{16}$ O in the fixed-target $^{208}$ Pb-- $^{20}$ Ne and $^{208}$ Pb-- $^{16}$ O collisions at $s_{_{NN}}$ = 68.5 GeV, using the parton transport model AMPT. The results of two- and four-particle cumulants of anisotropic flow demonstrate a robust $α$ -clustering signature that persists regardless of the complex dynamic evolution of the created systems. This study highlights the significant impact of the LHCb SMOG (SMOG2) project in discovering the $α$ -clustering signature of light nuclei at relativistic energies.
Comments:
7 pages, 3 figures
Subjects:
Nuclear Theory (nucl-th); Nuclear Experiment (nucl-ex)
arXiv:
2501.14852 [pdf]
PLB(2025)·12 citations
02
[Submitted on 24 Jan 2025]
Effects of sub-nucleonic fluctuations on the longitudinal structure of heavy-ion collisions
Oscar Garcia-Montero🇩🇪 · Sören Schlichting🇩🇪 · Jie Zhu🇩🇪
Sub-nuclear fluctuations in the initial state of heavy-ion collisions impact not only transverse long-range correlations of small systems, but also the creation of longitudinal structures, seen in particle detectors as longitudinal decorrelation observables. In this work, we study the emergence of long-range rapidity correlations in nuclear collisions based on the 3D resolved McDIPPER initial state model, and for the first time, connect it to experimental observables using the 3+1D viscous hydrodynamics framework CLVisc. We include different sources of fluctuations at the nucleon and subnucleon level and study the effects of these additional fluctuation sources on the longitudinal structure of relevant observables, such as the flow decorrelations and directed flow.
Subjects:
Nuclear Theory (nucl-th); High Energy Physics — Phenomenology (hep-ph)
arXiv:
2501.14872 [pdf]
PRD(2025)·12 citations
03
[Submitted on 24 Jan 2025]
The 3- $α$ and 4- $α$ particle systems within short-range Effective Field Theory
E. Filandri · M. Viviani · L. Girlanda · A. Kievsky · L.E. Marcucci
$^{12} C$ and $^{16} O$ nuclei represent essential elements for life on Earth. The study of their formation plays a key role in understanding heavy element nucleosynthesis and stellar evolution. In this paper we present the study of $^{12} C$ and $^{16} O$ nuclei as systems composed of $α$ -particle clusters using the short-range effective field theory approach. The fundamental and excited states of the studied nuclei are calculated within an ab-initio approach, using the Hyperspherical Harmonics method. Thanks to the two-body potential and fine-tuning of the three-body force, we have found the $^{12} C$ system nicely reproduced by theory. However, for the $^{16} O$ case, it is necessary to include a 4-body force in order to achieve agreement with the experimental data.
Subjects:
Nuclear Theory (nucl-th)
arXiv:
2501.14897 [pdf]
PRC(2025)·0 citations
04
[Submitted on 25 Jan 2025]
Observing short-range correlations in nuclei through $ρ^{0}$ photo-production
Phoebe Sharp🇺🇸 · Axel Schmidt🇺🇸
Short-range correlations (SRCs) are a universal feature of nuclear structure. A wide range of measurements, primarily using electron scattering, have revealed SRC properties, such as their abundance in different nuclei, as well as the strong preference for proton-neutron pairing over proton-proton or neutron-neutron pairing. Despite the inherent complexity of many-body systems, a number of the salient features of electron scattering measurements are described by a simple, factorized theory called Generalized Contact Formalism. A key element of this theory, the factorization of the interaction with a hard probe, has yet to be tested. An experiment conducted at Jefferson Lab in 2021 collected data from scattering a tagged photon beam, with an energy up to 10 GeV, from several nuclear targets, measuring final state particles in the large-acceptance GlueX spectrometer. In this paper, we propose a test of probe factorization by measuring cross section ratios sensitive to proton-proton pair prevalence and relative SRC abundances in $^{4}$ He and $^{12}$ C. We present GCF predictions of the observables and make projections of the expected precision the experiment can achieve.
Comments:
17 pages, 6 figures
Subjects:
Nuclear Theory (nucl-th); Nuclear Experiment (nucl-ex)
arXiv:
2501.15229 [pdf]
EPJA(2025)·2 citations
05
[Submitted on 25 Jan 2025]
A hitchhiker's guide to nuclear polarization in muonic atoms
Mikhail Gorchtein🇩🇪
I consider the so-called nuclear polarization correction to the 1S-levels in light to intermediate muonic atoms. An easy to use recipe to compute it is given. The calculation includes the effect of the nucleon polarization, i.e. the contribution from inelastic states in the hadronic range, and Coulomb corrections beyond the leading logarithm approximation to both nuclear and nucleon polarization. I provide numerical estimates for $4 \leq Z \leq 41$ , compare to the estimates in the literature and discuss the need for future improvements.
Comments:
Revised version accepted for publication as a PRC letter
Subjects:
Nuclear Theory (nucl-th); Nuclear Experiment (nucl-ex); Atomic Physics (physics.atom-ph)
arXiv:
2501.15274 [pdf]
PRC(2026)·12 citations
06
[Submitted on 26 Jan 2025]
Shear Viscosity of Collider-Produced QCD Matter II: Comparing a Multi-Component Chapman-Enskog Framework with AMPT in Full Equilibrium
Noah M. MacKay🇩🇪
Transport properties of the quark-gluon plasma are instrumental to testing perturbative quantum chromodynamics and understanding the extreme conditions of relativistic heavy-ion collisions. This study presents an analytical investigation of the shear viscosity $η$ and the shear viscosity-to-entropy density ratio $η / s$ of the QGP using a novel multi-component Chapman-Enskog framework assuming full thermalization. The approach incorporates species-specific contributions from gluons and (anti-)quarks into the plasma shear viscosity, temperature-dependent running parameters for the Debye mass and strong coupling, and a time-dependent cooling model. Our findings show that both $η$ and $η / s$ are enhanced by the inclusion of (anti-)quarks with gluons, and the parameters decrease over time due to the cooling and expansion of the QGP. These results align with perturbative QCD predictions, offering a more optimistic representation of QGP transport properties under dynamic conditions. This multi-component framework is compared with a multi-phase transport model that treats the QGP as a gluon gas with (anti-)quark augmentation.
Comments:
(Version 1): 13 pages, 3 figures, 1 table
Subjects:
Nuclear Theory (nucl-th)
arXiv:
2501.15658 [pdf]
0 citations
07
[Submitted on 27 Jan 2025]
Investigating the pion emission source in pp collisions using the AMPT model with sub-nucleon structure
Dong-Fang Wang🇨🇳 · Mei-Yi Chen🇨🇳 · Yu-Gang Ma🇨🇳 · Qi-Ye Shou🇨🇳 · Song Zhang🇨🇳 · Liang Zheng🇨🇳
The measurement of momentum correlations of identical pions serves as a fundamental tool for probing the space-time properties of the particle emitting source created in high-energy collisions. Recent experimental results have shown that, in pp collisions, the size of the one-dimensional primordial source depends on the transverse mass (\mt) of hadron pairs, following a common scaling behavior, similar to that observed in Pb--Pb collisions. In this work, a systematic study of the \pipi source function and correlation function is performed using the multiphase transport model (AMPT) to understand the properties of the emitting source created in high multiplicity pp collisions at $s = 13$ TeV. The \mt scaling behavior and pion emission source radii measured by ALICE experiment can be well described the model with sub-nucleon structure. These studies shed new light on the understanding of the effective size of the \pipi emission source and on studying the intensity interferometry in small systems with a transport model.
Comments:
10 pages, 11 figures
Subjects:
Nuclear Theory (nucl-th); Nuclear Experiment (nucl-ex)
arXiv:
2501.15776 [pdf]
Nucl.Sci.Tech.(2025)·7 citations
08
[Submitted on 27 Jan 2025]
Towards constraining QCD phase transitions in neutron star interiors: Bayesian Inference with TOV linear response analysis
Ronghao Li🇨🇳 · Sophia Han🇨🇳 · Zidu Lin🇺🇸 · Lingxiao Wang🇯🇵 · Kai Zhou🇨🇳 · Shuzhe Shi🇨🇳
The potential hadron-to-quark phase transition in neutron stars has not been fully understood as the property of cold, dense, and strongly interacting matter cannot be theoretically described by the first-principle perturbative calculations, nor have they been systematically measured through terrestrial low-to-intermediate energy heavy-ion experiments. Given the Tolman--Oppenheimer--Volkoff (TOV) equations, the equation of state (EoS) of the neutron star (NS) matter can be constrained by the observations of NS mass, radius, and tidal deformability. However, large observational uncertainties and the limited number of observations currently make it challenging to strictly reconstruct the EoS, especially to identify interesting features such as a strong first-order phase transition. In this work, we study the dependency of reconstruction quality of the phase transition on the number of NS observations of mass and radius as well as their uncertainty, based on a fiducial EoS. We conquer this challenging problem by constructing a neural network, which allows one to parametrize the EoS with minimum model-dependency, and by devising an algorithm of parameter optimization based on the analytical linear response analysis of the TOV equations. This work may pave the way for the understanding of the phase transition features in NSs using future $x$ -ray and gravitational wave measurements.
Comments:
The data for the plots are openly available: https://doi.org/10.5281/zenodo.15086456
Subjects:
Nuclear Theory (nucl-th); High Energy Astrophysical Phenomena (astro-ph.HE); High Energy Physics — Theory (hep-th)
arXiv:
2501.15810 [pdf]
PRD(2025)·18 citations
09
[Submitted on 27 Jan 2025]
Core screening effect in knockout reactions
Shichang Li · Junchen Pei · Danyang Pang
The systematic quenching of spectroscopic factors in terms of separation energy asymmetry in single-nucleon knockout reactions remains a puzzle. We propose a core screening effect to consider the hindrance when strongly bound nucleons in the projectile nucleus are removed by the heavy-ion target. The core screening effect is simulated as a density dependent suppression of single-particle wave functions inside the core of projectile. Our study shows that the parameterized core screening effect can significantly reduce the isospin dependence of quenching factors, offering insights into nuclear reaction mechanisms.
Comments:
5 pages, 3 figures, submitted
Subjects:
Nuclear Theory (nucl-th)
arXiv:
2501.15909 [pdf]
0 citations
10
[Submitted on 27 Jan 2025]
The correlation between the $α$ -cluster separation and the neutron S-factor in $^{12}$ Be
Zhilian Cai · Qing Zhao · Zaihong Yang · Masaaki Kimura · Bo Zhou · Seung-heon Shin
The reduced width amplitudes (RWA) and the spectroscopic factor (S-factor) of $α$ -cluster and valence neutron in $^{12}$ Be are calculated by the generator coordinates method (GCM) with the cluster model. By fixing the distance between the $α$ -clusters' generated coordinates, we make a theoretical experiment to analyze the relationship between the $α$ -clustering separation and the orbital occupation of the valence neutron in $^{12}$ Be. The analysis of the results shows that the percentage of the $σ$ orbital occupation in $^{12}$ Be is positively related to the clustering separation.
Comments:
5 pages, 6 figures
Subjects:
Nuclear Theory (nucl-th)
arXiv:
2501.15974 [pdf]
PRC(2025)·0 citations
11
[Submitted on 27 Jan 2025]
Cluster configurations in Li isotopes in the variation of multi-bases of the antisymmetrized molecular dynamics
Takayuki Myo · Mengjiao Lyu · Qing Zhao · Masahiro Isaka · Niu Wan · Hiroki Takemoto · Hisashi Horiuchi · Akinobu Dote
We investigate the cluster configurations in Li isotopes, which are described in the optimization of the multi-Slater determinants of the antisymmetrized molecular dynamics. Each Slater determinant in the superposition is determined simultaneously in the variation of the total energy. The configurations of the excited states are obtained by imposing the orthogonal condition to the ground-state configurations. In Li isotopes, various cluster configurations are confirmed and are related to the thresholds of the corresponding cluster emissions. For $^{5}$ Li, we predict the $^{3}$ He+ $d$ clustering in the excited state as well as the mirror state of $^{5}$ He with $^{3}$ H+ $d$ . For $^{6 - 9}$ Li, various combinations of the clusters are obtained in the ground and excited states, and the superposition of these basis states reproduces the observed energy spectra. For $^{9}$ Li, we predict the linear-chain states consisting of various cluster configurations at 10--13 MeV of the excitation energy.
Comments:
23 pages, 19 figures
Subjects:
Nuclear Theory (nucl-th); Nuclear Experiment (nucl-ex)
arXiv:
2501.16009 [pdf]
PTEP(2025)·10 citations
12
[Submitted on 27 Jan 2025]
Imaging nuclei by smashing them at high energies: how are their shapes revealed after destruction?
Jiangyong Jia🇺🇸
High-energy nuclear collisions have recently emerged as a promising ``imaging-by-smashing'' approach that may reveal the intrinsic shapes of atomic nuclei. Here, I outline a conceptual framework for this technique, explaining how nuclear shapes are encoded during quark-gluon plasma formation and evolution, and how they can be decoded from final-state particle distributions. I highlight the method's potential to advance our understanding of both nuclear structure and quark-gluon plasma physics.
Comments:
8 pages, 5 figures, replace with published version
Subjects:
Nuclear Theory (nucl-th); High Energy Physics — Phenomenology (hep-ph); Nuclear Experiment (nucl-ex); physics.atm-clus (physics.atm-clus); physics.chem-ph (physics.chem-ph)
arXiv:
2501.16071 [pdf]
Rept.Prog.Phys.(2025)·14 citations
13
[Submitted on 27 Jan 2025]
Correlations between nuclear incompressibility, liquid-gas critical point, and quarkyonic transition
Artemiy Lysenko🇺🇦 · Mark I. Gorenstein🇺🇦 · Tripp Moss🇺🇸 · Roman Poberezhniuk🇺🇦 · Volodymyr Vovchenko🇺🇸
We systematically probe different parametrizations of the attractive nuclear force based on real gas models to construct the nuclear matter equation of state. In each of the cases, the repulsion between nucleons is treated in the framework of excluded volume, and interaction parameters are fitted to the empirical properties of the nuclear ground state. We calculate the critical temperature $T_{c}$ and critical particle number density $n_{c}$ , and find that they are strongly correlated. Both are also correlated with the incompressibility $K_{0}$ in the nuclear ground state. We also include a quarkyonic matter phase in the quasiparticle description and investigate the relationships among $K_{0}$ , transition density to the quarkyonic phase, $n_{t r}$ , and corresponding peak in the speed of sound, $v_{s, max}^{2}$ . At each density, the quark fraction is found by minimizing the energy density. We find that both $n_{t r}$ and $v_{s, max}^{2}$ are negatively correlated with $K_{0}$ , $n_{c}$ , and $T_{c}$ .
Comments:
9 pages, 4 figures, 3 tables
Subjects:
Nuclear Theory (nucl-th)
arXiv:
2501.16225 [pdf]
PRC(2025)·3 citations

Affiliations

first authorsco-authorsvia INSPIRE