Nuclear Theory·nucl-th

Wednesday·July 23, 2025

9 papers—5 primary·4 cross-listed

01
[Submitted on 22 Jul 2025]
Symmetric-asymmetric collision comparison: disentangling nuclear structure and subnucleonic structure effects for small system flow
Shengli Huang🇺🇸 · Jiangyong Jia🇺🇸 · Chunjian Zhang🇺🇸
Previous flow measurements in small collision systems were mostly based on highly asymmetric collisions ( $p$ +Pb, $p$ +Au, $d$ +Au, $^{3}$ He+Au), where both nuclear structure and subnucleonic fluctuations are important. Comparing these asymmetric systems with the newly available symmetric $^{16}$ O+ $^{16}$ O collisions at RHIC and LHC provides a unique opportunity to disentangle these two contributions. Using Glauber models incorporating both nucleon and quark-level substructure, we analyze multiplicity distributions and initial-state estimators: eccentricities $ε_{n}$ for anisotropic flow $v_{n}$ and inverse transverse size $d_{⊥}$ for radial flow. We find that subnucleonic fluctuations impact O+O collisions differently from asymmetric systems, creating specific patterns in flow observables that enable disentangling the competing contributions. Such experimental comparisons will reduce uncertainties in the initial conditions and improve our understanding of the properties of the QGP-like medium produced in small systems.
Comments:
6 pages, 4 figures, plus an appendix
Subjects:
Nuclear Theory (nucl-th); High Energy Physics — Phenomenology (hep-ph); Nuclear Experiment (nucl-ex)
arXiv:
2507.16162 [pdf]
PLB(2025)·6 citations
02
[Submitted on 22 Jul 2025]
Charged Particle Scattering in Renormalizable Pionless Effective Field Theory at Next-to-Leading Order: The $p d$ , $dd$ , and $p^{3} He$ Case
Matúš Rojik🇨🇿 · Martin Schäfer🇨🇿 · Mirko Bagnarol🇮🇱 · Nir Barnea🇮🇱
We formulate a renormalizable pionless effective field theory (Pionless EFT) with a non-perturbative treatment of the Coulomb interaction up to next-to-leading order (NLO) for few-nucleon systems. We extract scattering observables for charged clusters by employing two-, three-, and four-body contact interactions and using the stochastic variational method with a Coulomb-corrected harmonic oscillator trap. Our NLO results yield a $p d$ spin-quartet scattering length and effective range of $a_{p d}^{3/2} = 12.76 (29) fm$ and $r_{p d}^{3/2} = 1.17 (7) fm$ ; for $dd$ scattering in the spin-quintet channel, we find $a_{dd}^{2} = 6.26 (3) fm$ and $r_{dd}^{2} = 1.41 (7) fm$ ; and for $p^{3} He$ scattering, the spin-singlet and spin-triplet channels are characterized by $a_{p^{3} He}^{0} = 11.26 (4) fm$ , $r_{p^{3} He}^{0} = 1.65 (26) fm$ and $a_{p^{3} He}^{1} = 9.06 (4) fm$ , $r_{p^{3} He}^{1} = 1.36 (25) fm$ , respectively. Our predictions exhibit mild cutoff dependence and agree well with existing experimental phase shift analyses and potential model calculations. This demonstrates the predictive power of (Pionless EFT) for charged few-nucleon systems.
Comments:
Data in figures are publicly accessible: DOI:10.5281/zenodo.16290109
Subjects:
Nuclear Theory (nucl-th)
arXiv:
2507.16250 [pdf]
PRC(2026)·2 citations
03
[Submitted on 22 Jul 2025]
Strangeness production in $O + O$ collisions at $s_{NN} = 7$ TeV using various model approaches
J. Singh · M. U. Ashraf · A. M. Khan · S. Kabana
We present the predictions of various observables for strange ( $K_{S}^{0}$ , $Λ$ ( $Λ$ )) and multi-strange hadrons ( $Ξ^{-}$ ( $Ξ^{+}$ ), $ϕ$ , and $Ω^{-}$ ( $Ω^{+}$ )) using the recently updated 3+1D hydrodynamics-based EPOS4 framework and AMPT model. In this study, we report the transverse momentum ( $p_{T}$ ) spectra, particle yields ( $d N / d y$ ), and $p_{T}$ integrated yield ratios relative to pions for $O + O$ collisions at $s_{NN} = 7$ ~TeV. The results reveal that there are indications of stronger radial flow in EPOS4 compared to AMPT. We observe a final state multiplicity overlap with small ( $p + p$ and $p + P b$ ) and large ( $P b + P b$ ) collision systems.
Comments:
8 Pages, 4 Figures
Subjects:
Nuclear Theory (nucl-th); High Energy Physics — Phenomenology (hep-ph)
arXiv:
2507.16266 [pdf]
International Journal of Modern Physics E…·2 citations
04
[Submitted on 22 Jul 2025]
Anisotropic flow predictions for identified and strange hadrons in $O + O$ collisions at $s_{NN}$ = 7 TeV using model approaches
Jagbir Singh🇨🇱 · M. U. Ashraf🇺🇸 · A. M. Khan🇺🇸 · S. Kabana🇨🇱
In this study, we report the predictions for the flow observables for different centrality classes in $O + O$ collisions. Our predictions utilize two different approaches, hydrodynamic and transport models, to analyze the behavior of the flow coefficients for identified ( $π^{\pm}$ , $K^{\pm}$ and $p (p)$ ) and strange ( $K_{S}^{0}$ , $Λ$ ( $Λ$ ), $Ω^{-}$ ( $Ω^{+}$ ), $Ξ^{-}$ ( $Ξ^{+}$ ), $ϕ$ ) hadrons. We explore particle-by-particle flow and compare the response of the system to initial conditions across various models, which provide insights into the underlying partonic and hadronic dynamics. The study presents comparisons of flow harmonics with the existing experimental measurements and demonstrates how $O + O$ collisions can serve as a benchmark to understand the transition from small to large systems, contributing to our knowledge of the Quark-Gluon Plasma (QGP) and collective phenomena in heavy-ion collisions.
Comments:
4 Pages, 3 Figues, DAE-HEP 2024 Conference
Subjects:
Nuclear Theory (nucl-th); High Energy Physics — Phenomenology (hep-ph)
arXiv:
2507.16273 [pdf]
Springer Proc.Phys.(2026)·2 citations
05
[Submitted on 22 Jul 2025]
Alpha clustering in warm and dense nuclear matter from heavy-ion collisions
Rui Wang🇨🇦 · Zhen Zhang🇨🇦 · Yu-Gang Ma🇨🇦 · Lie-Wen Chen🇨🇦 · Che Ming Ko🇨🇦 · Kai-Jia Sun🇨🇦
Although light nuclear clusters are known to affect the properties of warm and dilute nuclear matter, their role in warm and dense nuclear matter remains unclear due to the lack of experimental evidence for their modifications by the Mott effect in such an environment. To address this issue, we resort to intermediate-energy heavy-ion collisions, where light clusters are mainly produced in the transiently formed warm and dense matter. A kinetic approach, which includes dynamically the formation and dissociation of light clusters, is employed to deduce the strength of the Mott effects and the $α$ -particle fraction in warm and dense nuclear matter from the light-nuclei yields measured by the FOPI Collaboration in central Au $+$ Au collisions at energies of $0.25 A$ to $0.6 A GeV$ . We find an unexpectedly abundant $α$ clustering in this environment, which will have profound implications for modeling the nuclear equation of state and describing supernovae and neutron star mergers.
Comments:
6 pages, 3 figures
Subjects:
Nuclear Theory (nucl-th); High Energy Astrophysical Phenomena (astro-ph.HE); Nuclear Experiment (nucl-ex)
arXiv:
2507.16613 [pdf]
PRL(2026)·14 citations

Affiliations

first authorsco-authorsvia INSPIRE

Symmetric-asymmetric collision comparison: disentangling nuclear structure and subnucleonic structure effects for small system flow

Charged Particle Scattering in Renormalizable Pionless Effective Field Theory at Next-to-Leading Order: The pd, dd, and p3He Case

Strangeness production in O+O collisions at sNN​​=7 TeV using various model approaches

Anisotropic flow predictions for identified and strange hadrons in O+O collisions at sNN​​ = 7 TeV using model approaches

Alpha clustering in warm and dense nuclear matter from heavy-ion collisions

Affiliations

Charged Particle Scattering in Renormalizable Pionless Effective Field Theory at Next-to-Leading Order: The $p d$ , $dd$ , and $p^{3} He$ Case

Strangeness production in $O + O$ collisions at $s_{NN} = 7$ TeV using various model approaches

Anisotropic flow predictions for identified and strange hadrons in $O + O$ collisions at $s_{NN}$ = 7 TeV using model approaches