Nuclear Theory·nucl-th

Friday·August 29, 2025

14 papers—7 primary·7 cross-listed

01
[Submitted on 27 Aug 2025]
Chiral restoration temperature at finite spin density in QCD
Pracheta Singha🇷🇴 · Victor E. Ambrus🇷🇴 · Sergiu Busuioc🇷🇴 · Aritra Bandyopadhyay🇷🇴 · Maxim N. Chernodub🇷🇴
We investigate the impact of a uniform spin density on the critical temperature of the chiral phase transition in finite-temperature QCD in the scope of the linear sigma model. We demonstrate that at a finite spin potential $μ_{Σ}$ , corresponding to a finite spin density, the predictive power of the model is challenged by an ambiguity associated with a contribution of the vacuum renormalization term to the free energy. Eliminating the regularization freedom through comparison with recent low- $μ_{Σ}$ lattice data, we extend the phase diagram of QCD at finite spin density to regions inaccessible to lattice simulations. We show that, as the spin potential increases, the temperature of the chiral crossover transition diminishes and the chiral crossover turns into a first-order transition at a second-order critical end-point $(T, μ_{Σ})_{CEP} ≃ (0.142, 0.098)$ GeV. With increasing spin potential, the critical temperature touches the zero-temperature axis at $μ_{Σ} = 0.310$ GeV, implying that the chiral symmetry is restored at higher potentials at any temperature.
Comments:
24 pages, 11 figures, ultimate speen scheme
Subjects:
Nuclear Theory (nucl-th); High Energy Physics — Theory (hep-th)
arXiv:
2508.20237 [pdf]
PRD(2026)·3 citations
02
[Submitted on 27 Aug 2025]
Configuration mixing effects on neutrinoless $β β$ -decay nuclear matrix elements
Kosuke Nomura🇯🇵
Mixing and coexistence of intrinsic nuclear shapes play an important role to determine the low-energy structure of heavy nuclei, and are expected to affect nuclear matrix elements (NMEs) of neutrinoless double beta ( $0 ν β β$ ) decay. This problem is addressed in the interacting boson model with configuration mixing that is formulated by using the nuclear energy density functional theory. It is shown that significant amounts of mixing of normal and deformed intruder configurations are present in the ground and excited $0^{+}$ states in the even-even nuclei that are parent or daughter nuclei of the $0 ν β β$ decay. An illustrative application to the $0 ν β β$ decays of $^{76}$ Ge, $^{96}$ Zr, $^{100}$ Mo, $^{116}$ Cd, and $^{150}$ Nd shows that the inclusion of the configuration mixing reduces the NMEs for most of the $0_{1}^{+}$ $\to$ $0_{1}^{+}$ $0 ν β β$ decays.
Comments:
8 pages, 6 figures, 2 tables
Subjects:
Nuclear Theory (nucl-th); Nuclear Experiment (nucl-ex)
arXiv:
2508.20323 [pdf]
PLB(2025)·3 citations
03
[Submitted on 28 Aug 2025]
Perturbative high-energy evolution in the IP-Glasma initial state
Heikki Mäntysaari🇫🇮 · Björn Schenke🇺🇸 · Chun Shen🇺🇸 · Wenbin Zhao🇺🇸
We include the perturbative JIMWLK energy evolution into the IP-Glasma initial state description used to simulate the early-time dynamics in heavy ion collisions. By numerically solving the JIMWLK equation on an event-by-event basis, we obtain the energy (Bjorken- $x$ ) dependent structure of the colliding nuclei. Combining the initial state with hydrodynamic simulations, this enables us to predict how observables evolve when moving from RHIC to LHC energies.
Comments:
4 pages. Talk by H.M at the Quark Matter 2025 conference
Subjects:
Nuclear Theory (nucl-th)
arXiv:
2508.20432 [pdf]
EPJ Web Conf.(2026)·1 citation
04
[Submitted on 28 Aug 2025]
$Ξ N N$ three-baryon force from SU(3) chiral effective field theory: A femtoscopic study
Gen Uratsu🇯🇵 · Tokuro Fukui🇯🇵 · Kazuyuki Ogata🇯🇵
Background: The development of SU(3) chiral effective field theory has opened the way to a systematic exploration of three-baryon forces (3BFs), a key ingredient in hypernuclear and dense matter physics. However, $Ξ N N$ 3BF based on SU(3) chiral EFT has not been studied until now. Purpose: We apply SU(3) chiral EFT to derive $Ξ N N$ potentials in momentum space. Then, we investigate how the $Ξ N N$ 3BF affects the correlation function of deuteron-- $Ξ^{-}$ pair created through heavy-ion collisions. Methods: To reduce the number of low-energy constants involved in the $Ξ N N$ potentials, we employ the decuplet saturation approximation, by which only two of them remain unconstrained. The deuteron-- $Ξ^{-}$ scattering is treated as an effective two-body problem with the $Ξ N N$ 3BF incorporated into the potential between the deuteron and $Ξ^{-}$ . Results: We found that the effect of the $Ξ N N$ 3BF on the deuteron-- $Ξ^{-}$ correlation function is at most about 4\%. This small effect is not primarily due to the loosely-bound nature of the deuteron. Instead, this is because the deuteron and $Ξ^{-}$ interact with each other mainly at low momentum, corresponding to peripheral scattering, where the influence of the $Ξ N N$ 3BF is limited. Conclusions: Since the correlation function shows limited sensitivity to the short-range 3BF, complementary approaches may be necessary.
Comments:
21 pages, 10 figures, 4 tables
Subjects:
Nuclear Theory (nucl-th); High Energy Physics — Phenomenology (hep-ph); Nuclear Experiment (nucl-ex)
arXiv:
2508.20498 [pdf]
PRC(2026)·0 citations
05
[Submitted on 28 Aug 2025]
Medium effects on the electromagnetic form factors of the $ρ$ meson
Parada T. P. Hutauruk🇰🇷 · Terry Mart🇮🇩 · Kazuo Tsushima🇧🇷
The dynamics of partons inside the light $ρ$ meson is found to be essential for its properties and internal structure, both in free space and in the nuclear medium. In this paper, we systematically investigate the in-medium structure changes of $ρ^{+}$ mesons within the covariant Nambu-Jona-Lasinio (NJL) model, utilizing the Schwinger proper-time regularization scheme. We solve the Bethe-Salpeter equations to guarantee the bound meson-state condition. At the quark level, the nuclear medium effects are also derived within the same NJL model to maintain a consistent approach with the in-medium $ρ^{+}$ meson electromagnetic form factors. To this end, we analyze the spacelike electromagnetic form factors of the $ρ^{+}$ meson in free space and in a nuclear medium. We find that the charge radius and quadrupole moment of the $ρ^{+}$ meson increase with increasing nuclear matter density, while the magnetic moment decreases, in agreement with the existing previous theoretical predictions. The enhancement of the $ρ^{+}$ meson charge radius at normal density relative to that in free space is about 11\% (0.08 fm), while the reduction of $ρ^{+}$ meson magnetic moment is about 8\% (0.20 $μ_{N}$ ). Our predictions for the charge radius, magnetic moment, and quadrupole moment of the $ρ^{+}$ meson in both free space and nuclear medium, remain challenging to be verified experimentally.
Comments:
19 pages, 7 figures, Table 1, published version
Subjects:
Nuclear Theory (nucl-th); High Energy Physics — Phenomenology (hep-ph)
arXiv:
2508.20501 [pdf]
PRD(2025)·7 citations
06
[Submitted on 28 Aug 2025]
Bottomonium transport in a strongly coupled quark-gluon plasma
Biaogang Wu🇺🇸 · Ralf Rapp🇺🇸
Quarkonium production in high-energy heavy-ion collisions remains a key probe of the quark-gluon plasma formed in these reactions, but the development of a fully integrated nonperturbative approach remains a challenge. Toward this end, we set up a semiclassical transport approach that combines nonperturbative reaction rates rooted in lattice-constrained $T$ -matrix interactions with a viscous hydrodynamic medium evolution. Bottomonium suppression is computed along trajectories in the hydrodynamic evolution while regeneration is evaluated via a rate equation extended to a medium with spatial gradients. The much larger reaction rates compared to previous calculations markedly enhance both dissociation and regeneration processes. This, in particular, requires a reliable assessment of bottomonium equilibrium limits and of the non-thermal distributions of the bottom quarks transported through the expanding medium. Within current uncertainties our approach can describe the centrality dependence of bottomonium yields measured in Pb-Pb ( $s_{_{NN}}$ =5.02\,TeV) collisions at the LHC, while discrepancies are found at large transverse momenta.
Subjects:
Nuclear Theory (nucl-th)
arXiv:
2508.20995 [pdf]
PLB(2026)·7 citations
07
[Submitted on 28 Aug 2025]
Far from equilibrium attractors in phase space
Michał Spaliński🇫🇮
The emergence of far from equilibrium, prehydrodynamic attractors is an important feature of boost-invariant flow in models of relativistic fluid dynamics, as well as in some microscopic theories. Originally, these attractors were defined in terms of attractor solutions, using a partial decoupling of the equations of motion that relied on using special variables. Reliance on such a decoupling restricts the class of systems that can be analysed. Instead of introducing special variables, here we directly leverage the singularity of the evolution equations at early proper time. This singularity is a consequence of boost invariance, which should be regarded as crucial physical input stemming from fundamental properties of particle production in QCD. We posit that it provides initial conditions which determine the attractor hypersurface in phase space, irrespective of whether the evolution equations can be partially decoupled or not. We validate this in a case where the equations of motion cannot be decoupled but the attractor can still be identified and governs the behaviour of generic solutions in a similar way to what happens in cases where attractor solutions exist.
Subjects:
Nuclear Theory (nucl-th)
arXiv:
2508.21039 [pdf]
5 citations

Affiliations

first authorsco-authorsvia INSPIRE

Chiral restoration temperature at finite spin density in QCD

Configuration mixing effects on neutrinoless ββ-decay nuclear matrix elements

Perturbative high-energy evolution in the IP-Glasma initial state

ΞNN three-baryon force from SU(3) chiral effective field theory: A femtoscopic study

Medium effects on the electromagnetic form factors of the ρ meson

Bottomonium transport in a strongly coupled quark-gluon plasma

Far from equilibrium attractors in phase space

Affiliations

Configuration mixing effects on neutrinoless $β β$ -decay nuclear matrix elements

$Ξ N N$ three-baryon force from SU(3) chiral effective field theory: A femtoscopic study

Medium effects on the electromagnetic form factors of the $ρ$ meson