Nuclear Theory·nucl-th

Monday·November 25, 2024

11 papers—4 primary·7 cross-listed

01
[Submitted on 22 Nov 2024]
Transverse and longitudinal spin alignment from color fields in heavy ion collisions
Di-Lun Yang🇹🇼
We analyze the spin alignment of vector mesons stemming from spin correlation of the quark and antiquark induced by background color fields in relativistic heavy ion collisions. The quark-coalescence equation relating the collision kernel of the vector-meson kinetic equation to spin alignment is expanded to the relativistic case. Focusing on the color-octet contribution, the spin alignment for $ϕ$ mesons from glasma fields with momentum dependence is investigated, where the scenarios for different spin quantization axes are considered. Moreover, we qualitatively analyze the spin alignment from isotropic color fields in the quark gluon plasma phase for comparison. In particular, we propose that the experimental measurement of spin alignment along the beam direction, dubbed as the longitudinal spin alignment, could be useful to identify the dominance of longitudinal spin correlation potentially led by the glasma effect in high-energy nuclear collisions.
Comments:
39 pages, 14 figures, typos corrected, minor revisions, published version
Subjects:
Nuclear Theory (nucl-th); High Energy Physics — Phenomenology (hep-ph)
arXiv:
2411.14822 [pdf]
PRD(2025)·12 citations
02
[Submitted on 22 Nov 2024]
Determining the minimal mass of a proto-neutron star with chirally constrained nuclear equations of state
Selina Kunkel🇩🇪 · Stephan Wystub🇩🇪 · Jürgen Schaffner-Bielich🇩🇪
The minimal masses and radii of proto-neutron stars during different stages of their evolution are investigated. In our work we focus on two stages, directly after the supernova shock wave moves outwards, where neutrinos are still captured in the core and the lepton per baryon ratio is fixed to $Y_{L} = 0.4$ , and a few seconds afterwards, when all neutrinos have left the star. All nuclear equations of state used for this purpose fulfill the binding energy constraints from chiral effective field theory for neutron matter at zero temperature. We find for the neutrino-trapped case higher minimal masses than for the case when neutrinos have left the proto-neutron star. Thermal effects, here in the form of a given constant entropy per baryon $s$ , have a smaller effect on increasing the minimal mass. The minimal proto-neutron star mass for the first evolutionary stage with $Y_{L} = 0.4$ and $s = 1$ amounts to $M_{min} \sim 0.62 M_{⊙}$ and for the stage without neutrinos and $s = 2$ to $M_{min} \sim 0.22 M_{⊙}$ rather independent on the nuclear equation of state used. We also study the case related to an accretion induced collapse of a white dwarf where the initial lepton fraction is $Y_{L} = 0.5$ and observe large discrepancies in the results of the different tables of nuclear equations of state used. Our finding points towards a thermodynamical inconsistent treatment of the nuclear liquid-gas phase transition for nuclear equations of state in tabular form demanding a fully generalized three-dimensional Gibbs construction for a proper treatment. Finally, we demonstrate that there is a universal relation for the increase of the proto-neutron star minimal mass with the lepton fraction for all nuclear equations of state used.
Comments:
29 pages, 8 figures, 2 tables
Subjects:
Nuclear Theory (nucl-th); High Energy Astrophysical Phenomena (astro-ph.HE)
arXiv:
2411.14930 [pdf]
PRC(2025)·10 citations
03
[Submitted on 22 Nov 2024]
Energy dependence of the deformed nuclear structure at small- $x$
Heikki Mäntysaari🇫🇮 · Pragya Singh🇫🇮
We quantify the effect of high-energy JIMWLK evolution on the deformed structure or heavy (Uranium) and intermediate (Ruthenium) nuclei. The soft gluon emissions in the high-energy evolution are found to drive the initially deformed nuclei towards a more spherical shape, although the evolution is slow ,especially for the longest distance-scale quadrupole deformation. We confirm a linear relationship between the squared eccentricity $ε_{n}^{2}$ and the deformation parameter $β_{n}^{2}$ in central collisions across the energy range covered by the RHIC and LHC measurements. The applied JIMWLK evolution is found to leave visible signatures in the eccentricity evolution that can be observed if the same nuclei can be collided at RHIC and at the LHC, or in rapidity-dependent flow measurements. Our results demonstrate the importance of including the Bjorken- $x$ dependent nuclear geometry when comparing simulations of the Quark Gluon Plasma evolution with precise flow measurements at high collision energies.
Comments:
9 pages, 10 figures
Subjects:
Nuclear Theory (nucl-th); High Energy Physics — Lattice (hep-lat); High Energy Physics — Phenomenology (hep-ph)
arXiv:
2411.14934 [pdf]
EPJC(2025)·8 citations
04
[Submitted on 22 Nov 2024]
Ab initio study of the beryllium isotopes $^{7}$ Be to $^{12}$ Be
Shihang Shen · Serdar Elhatisari · Dean Lee · Ulf-G. Meißner · Zhengxue Ren
We present a systematic ab initio study of the low-lying states in beryllium isotopes from 7Be to 12Be using nuclear lattice effective field theory with the N3LO interaction. Our calculations achieve good agreement with experimental data for energies, radii, and electromagnetic properties. We introduce a novel, model-independent method to quantify nuclear shapes, uncovering a distinct pattern in the interplay between positive and negative parity states across the isotopic chain. By combining Monte Carlo sampling of the many-body density operator with a novel nucleon-grouping algorithm, the prominent two-center cluster structures, the emergence of one-neutron halo, complex nuclear molecular dynamics such as {\pi} orbital and {\sigma} orbital, emerge naturally.
Comments:
7+9 pages, 4+5 figures
Subjects:
Nuclear Theory (nucl-th); Cosmology and Nongalactic Astrophysics (astro-ph.CO); High Energy Physics — Phenomenology (hep-ph); Nuclear Experiment (nucl-ex)
arXiv:
2411.14935 [pdf]
PRL(2025)·52 citations
05
[Submitted on 21 Nov 2024] (cross-list from hep-ph)
Constraining Jet Quenching in Heavy-Ion Collisions with Bayesian Inference
Alexandre Falcão🇳🇴 · Konrad Tywoniuk🇳🇴
Jet suppression and modification is a hallmark feature of heavy-ion collisions. This can be attributed to an accumulated set of effects, including radiative and elastic energy loss and reabsorption of thermalized energy within the jet cone, which are encoded in a quenching weight, determining the probability distribution for a shift of the $p_{T}$ (energy loss). We perform a data-driven analysis, based on Bayesian inference, to extract information about the energy-loss distribution experienced by propagating jets using generic and flexible parametrizations. We first establish the consistency between different data-sets and, thereby, provide evidence for the universality of the quark/gluon quenching weights for different observables. Furthermore, we extract that the color dependence of energy loss is slightly bigger than what expected from Casimir scaling, pointing to the importance of multi-parton quenching within high- $p_{T}$ jets at the LHC.
Comments:
25 pages, 19 figures
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Experiment (hep-ex); Nuclear Theory (nucl-th)
arXiv:
2411.14552 [pdf]
JHEP(2026)·6 citations
06
[Submitted on 14 Nov 2024] (cross-list from astro-ph.HE)
CompactObject: An open-source Python package for full-scope neutron star equation of state inference
Chun Huang🇺🇸 · Tuhin Malik🇵🇹 · João Cartaxo🇵🇹 · Shashwat Sourav🇺🇸 · Wenli Yuan🇨🇳 · Tianzhe Zhou🇨🇳 · Xuezhi Liu🇨🇳 · John Groger🇺🇸 · Xieyuan Dong🇨🇳 · Nicole Osborn🇺🇸 · Nathan Whitsett🇺🇸 · Zhiheng Wang🇺🇸 and 5 other authors
The CompactObject package is an open-source software framework developed to constrain the neutron star equation of state (EOS) through Bayesian statistical inference. It integrates astrophysical observational constraints from X-ray timing, gravitational wave events, and radio measurements, as well as nuclear experimental constraints derived from perturbative Quantum Chromodynamics (pQCD) and Chiral Effective Field Theory ( $χ$ EFT). The package supports a diverse range of EOS models, including meta-model like and several physics-motivated EOS models. It comprises three independent components: an EOS generator module that currently provides seven EOS choices, a Tolman-Oppenheimer-Volkoff (TOV) equation solver, that allows the determination of the Mass Radius and Tidal deformability as observables, and a comprehensive Bayesian inference workflow module, including a complete pipeline for implementing EOS Bayesian inference. Each component can be used independently in different scientific research contexts, such as nuclear physics and astrophysics. In addition, CompactObject is designed to work in synergy with existing software such as CompOSE, allowing the use of the CompOSE EOS database to extend the EOS options available.
Comments:
submitted to JOSS, Github page: https://github.com/ChunHuangPhy/CompactObject , Documentation: https://chunhuangphy.github.io/CompactObject/
Subjects:
High Energy Astrophysical Phenomena (astro-ph.HE); Instrumentation and Methods for Astrophysics (astro-ph.IM); Nuclear Theory (nucl-th)
arXiv:
2411.14615 [pdf]
26 citations
07
[Submitted on 22 Nov 2024] (cross-list from hep-lat)
Lattice gradient flows (de-)stabilizing topological sectors
Yuya Tanizaki🇯🇵 · Akio Tomiya🇯🇵 · Hiromasa Watanabe🇯🇵
We investigate the stability of topological charge under gradient flow taking the admissibility condition into account. For the $S U (2)$ Wilson gauge theory with $β = 2.45$ and $L^{4} = 1 2^{4}$ , we numerically show that the gradient flows with the Iwasaki and DBW2 gauge actions stabilize the topological sectors significantly, and they have qualitatively different behaviors compared with the Wilson and tree-level Symanzik flows. By considering the classical continuum limit of the flow actions, we discuss that the coefficient of dimension- $6$ operators has to be positive for stabilizing the one-instanton configuration, and the Iwasaki and DBW2 actions satisfy this criterion while the Wilson and Symanzik actions do not. Moreover, we observe that the DBW2 flow stabilizes the topological sectors at the very early stage of the flow ( $t^\approx 0.5$ -- $1$ ), suggesting that a further systematic investigation of the DBW2 flow is warranted to confirm its computational efficiency in determining the gauge topology.
Comments:
1+27 pages, 13 figures, remarks in Section 4 and an analysis in Appendix A are added
Subjects:
High Energy Physics — Lattice (hep-lat); High Energy Physics — Theory (hep-th); Nuclear Theory (nucl-th)
arXiv:
2411.14812 [pdf]
JHEP(2025)·11 citations
08
[Submitted on 22 Nov 2024] (cross-list from hep-ph)
Gluon Saturation Effects in Exclusive Heavy Vector Meson Photoproduction
Jani Penttala🇺🇸 · Christophe Royon🇺🇸
We study exclusive $J / ψ$ and $Υ$ photoproduction for proton and Pb targets in the high-energy limit, with the energy dependence computed using the linear Balitsky-Fadin-Kuraev-Lipatov and the nonlinear Balitsky-Kovchegov evolution equations. The difference between these two evolution equations can be directly attributed to gluon saturation physics. We find that for proton targets there is no difference between the two approaches at the energies of the currently available data, while for Pb targets in $J / ψ$ production the data shows a clear preference for the evolution with gluon saturation.
Comments:
7 pages, 6 figures; v2: matches published version
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2411.14815 [pdf]
PLB(2025)·18 citations
09
[Submitted on 22 Nov 2024] (cross-list from hep-ph)
Relative Hadron Yields in HRG With Medium Modification
Nasir Ahmad Rather🇮🇳 · Sameer Ahmad Mir🇮🇳 · Iqbal Mohi Ud Din🇮🇳 · Saeed Uddin🇮🇳
In the framework of a constituent quark mass model, the modified baryon masses are incorporated into the hadron resonance gas (HRG) based analysis of the like mass particle ratios in ultra relativistic nucleus-nucleus collisions (URNNC) over a wide range of collision energy. In addition we have incorporated an essential feature of the hadronic interaction at short distance, i.e. the hard-core repulsion by using the standard excluded volume type approach. We have extracted the chemical freeze-out conditions. The resulting freeze-out line in our case is compared with those obtained earlier using different model approaches. The correlation between $k^{-} / k^{+}$ and $p ˉ / p$ ratios is also studied.
Comments:
10 pages, 13 figures, 2 tables
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2411.14826 [pdf]
Int.J.Mod.Phys.A(2025)·4 citations
10
[Submitted on 22 Nov 2024] (cross-list from astro-ph.HE)
Bayesian inference of strangeon matter using the measurements of PSR J0437-4715 and GW190814
Wen-Li Yuan🇨🇳 · Chun Huang🇺🇸 · Chen Zhang🇨🇳 · Enping Zhou🇨🇳 · Renxin Xu🇨🇳
The observations of compact star inspirals from LIGO/Virgo combined with mass and radius measurements from NICER provide a valuable tool to study the highly uncertain equation of state (EOS) of dense matter at the densities characteristic of compact stars. In this work, we constrain the solid states of strange-cluster matter, called strangeon matter, as the putative basic units of the ground state of bulk strong matter using a Bayesian statistical method, incorporating the mass and radius measurements of PSR J0030+0451, PSR J0740+6620, and the recent data for the $1.4 M_{⊙}$ pulsar PSR J0437-4715. We also include constraints from gravitational wave events GW170817 and GW190814. Under the prior assumption of a finite number of quarks in a strangeon, $N_{q}$ , our analysis reveals that current mass-radius measurements favor a larger $N_{q}$ . Specifically, the results support the scenario where a strangeon forms a stable bound state with $N_{q} = 18$ , symmetric in color, flavor, and spin spaces, compared to the minimum $N_{q}$ prior. The comparative analyses of the posterior EOS parameter spaces derived from three-parameter model and two-parameter model demonstrate a consistent prediction under identical observational constraints. In particular, our results indicate that the most probable values of the maximum mass are found to be $3.5 8_{- 0.12}^{+ 0.16} M_{⊙}$ ( $3.6 5_{- 0.16}^{+ 0.18} M_{⊙}$ ) at $90%$ confidence level for three-parameter (two-parameter) EOS considering the constraints of GW190814. The corresponding radii for $1.4 M_{⊙}$ and $2.1 M_{⊙}$ stars are $12.0 4_{- 0.31}^{+ 0.27} km$ ( $12.1 6_{- 0.31}^{+ 0.26} km$ ) and $13.4 3_{- 0.32}^{+ 0.31} km$ ( $13.6 0_{- 0.34}^{+ 0.29} km$ ), respectively. This result may impact interestingly on the research of multiquark states, which could improve our understanding of the nonperturbative strong force.
Comments:
10 pages, 4 figures, Phys. Rev. D (2025) published
Subjects:
High Energy Astrophysical Phenomena (astro-ph.HE); Nuclear Theory (nucl-th)
arXiv:
2411.14938 [pdf]
PRD(2025)·17 citations
11
[Submitted on 22 Nov 2024] (cross-list from hep-ph)
Hyperons in neutron star mergers
Hristijan Kochankovski🇪🇸 · Angels Ramos🇪🇸 · Laura Tolos🇪🇸 · Sebastian Blacker🇩🇪 · Andreas Bauswein🇩🇪
We discuss the effects induced by the potential presence of hyperons in hot and ultra-dense matter within the context of neutron star mergers. Specifically, we address their effect on the dominant post-merger frequency of the gravitational waves. By performing a simulation campaign with a large sample of hyperonic and nucleonic equations of state, we explicitly show that the unique thermal behavior of hyperonic equations of state results in a systematic shift of the dominant frequency with respect to the nucleonic reference level. The predicted shift has values of up to 150 Hz, and it could be detected with the newest generations of gravitational wave detectors. Thus this approach opens a new path for signaling the presence of hyperons in neutron star remnant matter.
Comments:
6 pages, 2 figures, Contribution to the proceedings of the 10th International Conference on Quarks and Nuclear Physics (QNP2024)
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2411.14978 [pdf]
PoS(2025)·2 citations

Affiliations

first authorsco-authorsvia INSPIRE