Nuclear Theory·nucl-th

Wednesday·May 13, 2026

13 papers—5 primary·8 cross-listed

06
[Submitted on 11 May 2026] (cross-list from hep-ph)
Gluon Entanglement Entropy inside a Nucleon: A Toy Model
David Horn · Berndt Müller · Xiaojun Yao
We construct a toy model of a nucleon, in which three static quarks interact via a SU(3) gauge field on a planar honeycomb lattice. The dynamics of the gauge field is described by the Kogut-Susskind Hamiltonian, truncated to the lowest three SU(3) irreducible representations. We show that the internal structure of the toy nucleon reflects salient features of the physical nucleon state. We then find the entanglement entropy of the gauge field within the nucleon state and compute its time evolution after a quench, in which all three valence quarks are suddenly removed. We show that the entanglement entropy in the final state is dominated by the dynamically generated contribution rather than the initial state entropy.
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2605.11171 [pdf]
3 citations
07
[Submitted on 11 May 2026] (cross-list from quant-ph)
Quantum tunneling, global phases and the limits of classical action reconstructions
Chong Qi · Mário B. Amaro
It was proposed recently that the Schrödinger wave function can be reconstructed exactly from a discrete superposition of classical action branches weighted by associated classical densities, without semiclassical approximations. We examine this construction for quantum tunneling through finite potential barriers and for quantum phase phenomena. Although formally consistent when the Hamilton-Jacobi equation admits globally defined real branches, the construction breaks down in classically forbidden regions where no real classical action exists. Using rectangular and Coulomb barrier tunneling in alpha decay and nuclear fusion, we show that the wave function requires either a non-vanishing quantum potential or complex-valued action. The growing barrier component fixed by global boundary conditions is essential for transmission and cannot arise from local real classical trajectories alone. Berry phase, flux quantization, Josephson tunneling, and dc SQUID interference likewise impose global phase constraints absent from local classical action transport.
Subjects:
Quantum Physics (quant-ph); Superconductivity (cond-mat.supr-con); Nuclear Theory (nucl-th)
arXiv:
2605.11252 [pdf]
0 citations
08
[Submitted on 12 May 2026] (cross-list from nucl-ex)
Multiple shape coexistence near Sn118: First 03+ lifetime measurement
F. Wu🇨🇦 · C. R. Ding🇨🇳 · C. Andreoiu🇨🇦 · V. Karayonchev🇺🇸 · Y. Li🇨🇳 · C. Michelagnoli🇫🇷 · C. M. Petrache🇨🇦 · J.-M. Régis · J. M. Yao🇨🇳 · M. Beuschlein🇩🇪 · G. Colombi🇫🇷 · J.M. Daugas🇫🇷 and 8 other authors
The intruder bands in Sn isotopes, built on the 2p-2h excitation across the $Z = 50$ proton shell gap, are well-known examples of shape coexistence near the neutron mid-shell region. Spectroscopic signatures for shape coexistence include enhanced $E 0$ transitions between the $0^{+}$ band heads. However, the underlying shape coexistence and mixing has been unclear because lifetime information for the excited $0^{+}$ states was incomplete in $^{118}$ Sn. We thus present here the first measurement of the $0_{3}^{+}$ lifetime in $^{118}$ Sn using the fast-timing technique following thermal-neutron capture. The observed enhancement in $ρ^{2} (E 0; 0_{3}^{+} \to 0_{2}^{+})$ of 150(30) milliunits provides compelling indications for multiple shape coexistence in $^{118}$ Sn. Additionally, three distinct shapes in $^{116, 118, 120}$ Sn naturally emerged in theoretical calculations based on the quantum-number-projected generator coordinate method employing a relativistic energy density functional.
Comments:
7 pages, 2 figures, Supplemental material: https://journals.aps.org/prc/supplemental/10.1103/npjn-xpfj/Supp.pdf
Subjects:
Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
arXiv:
2605.11412 [pdf]
PRC(2026)·0 citations
09
[Submitted on 12 May 2026] (cross-list from hep-ph)
In-medium Y(1S,2S,3S) suppression in Pb-Pb collisions at sqrt(s_NN)=5.02 TeV
J. Majonica🇩🇪 · G. Wolschin🇩🇪
We present model calculations for the in-medium suppression of the Y(1S,2S,3S) states in sqrt(s_NN)=5.02 TeV Pb-Pb collisions at the Large Hadron Collider in comparison with recent CMS data for all three spin-triplet s-wave states. The model parameters initial central temperature, and formation times for the Y(nS) states are determined in simultaneous chi^2 minimizations with respect to the data, such that the sequential centrality- and transverse-momentum-dependent suppression of the observed states is reproduced.
Comments:
7 pages, 4 figures; submitted to NPB
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2605.11765 [pdf]
NPB 1028, 117510 (2026)·0 citations
10
[Submitted on 12 May 2026] (cross-list from hep-ph)
Trace anomaly, effective degrees of freedom, and chemical potential effects near the QCD crossover
Yaroslav Krivenko-Emetov🇦🇹
A compact analytical scheme is presented for describing ultra-dense hadronic matter, which combines a multicomponent van der Waals (vdW)-type description with temperature-dependent effective degrees of freedom. Although the vdW formalism successfully reproduces interactions at finite density, in its standard form it cannot describe lattice-QCD thermodynamics, since it uses a fixed degeneracy. It is shown that a consistent description of the equation of state requires a temperature-dependent degeneracy $g (T)$ and an effective chemical potential $μ (T)$ . Within this approach, the trace anomaly (the trace of the energy-momentum tensor), i.e. the measure of nonconformality of the energy-momentum tensor normalized to $T^{4}$ , is naturally reproduced together with its peak structure near the crossover region. The effective chemical-potential sector becomes particularly important in baryon-rich matter, whereas for the mesonic sector a separate dynamical description of the degrees of freedom is required.
Comments:
8 pages, 2 figures. Contribution to the XXXIII Annual Scientific Conference of the Institute for Nuclear Research, Kyiv, Ukraine, May 25-29, 2026
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2605.11952 [pdf]
0 citations
11
[Submitted on 12 May 2026] (cross-list from hep-ph)
Photoproduction of $J /Ψ$ in peripheral Oxygen-Oxygen collisions
Pedro E. A. da Costa🇧🇷 · André V. Giannini🇧🇷 · Victor P. Gonçalves · Bruno D. Moreira🇧🇷
The photoproduction of $J /Ψ$ in peripheral Oxygen - Oxygen ( $O O$ ) collisions at the Large Hadron Collider (LHC) is investigated considering distinct assumptions for the modeling of the nuclear photon flux, overlap function and dipole - proton scattering amplitude. Predictions for the associated rapidity distributions and total cross - sections are presented. Our results indicate that the experimental study of the photoproduction of $J /Ψ$ in peripheral $O O$ collisions is, in principle, feasible. In addition, they point out that the combination of the results for this final state in $O O$ collisions with those obtained for $P b P b$ collisions will allow us to derive important constraints on the description of photon - induced process at peripheral collisions.
Comments:
15 pages, 4 figures, 4 tables
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Experiment (hep-ex); Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
arXiv:
2605.12123 [pdf]
0 citations
12
[Submitted on 12 May 2026] (cross-list from hep-th)
Necessary conditions for causality from linearized stability at ultra-high boosts
Shuvayu Roy🇮🇳 · Sukanya Mitra🇮🇳 · Rajeev Singh🇷🇴
In this work, we provide a novel method to constrain the causal parameter space of a relativistic hydrodynamic system exclusively from its linear stability analysis at non-zero momenta. Our approach exploits the Lorentz-invariant stability property of causal theories. In boosted frames, the dispersion relation exhibits a feature that we call `` $γ$ -suppression,'' whereby the higher-order terms in the wavenumber expansion are increasingly suppressed beyond leading order at large boosts. As a consequence, at near-luminal values of Lorentz boost, stability criteria at the spatially homogeneous limit are sufficient to identify the region of the parameter space that satisfies the necessary conditions of causality, even at non-zero momenta. After presenting the general hydrodynamic framework, we test the method in conformal Müller-Israel-Stewart theory and show that it provides an efficient way of deriving the necessary conditions of causality while remaining within the low-energy regime of hydrodynamic validity.
Comments:
18 pages, 14 figures
Subjects:
High Energy Physics — Theory (hep-th); Nuclear Theory (nucl-th)
arXiv:
2605.12291 [pdf]
2 citations
13
[Submitted on 12 May 2026] (cross-list from physics.atm-clus)
Natural and Dyson orbitals in small helium drops
N.K. Timofeyuk
The natural and Dyson orbitals are studied for small helium drops comprising 5 to 20 helium atoms interacting via a soft two-body gaussian potential. The wave functions of these drops have been obtained in the hyperspherical cluster model (HCM) which provides a correct description of the single-particle behaviour at large separations from the system. The natural orbitals are obtained from diagonalization of the nonlocal one-body density matrix, while Dyson orbitals are constructed by direct overlap of the wave functions of two drops differing by one boson. This overlap converges with increasing basis of the HCM. The shapes and occupancies of the natural orbitals as well as their link to Dyson overlaps and evolution with increasing number of atoms are discussed. Both natural and Dyson orbitals can be used to represent the density of the system. However, the natural orbitals representation is demonstrated to be superior. With increasing boson numbers the difference between Dyson and natural orbitals becomes less prominent and it is expected to disappear in infinitely large systems of identical bosons.
Comments:
Special Issue on Few-Body Physics in J. Phys. B: At. Mol. Opt. Phys. (2025)
Subjects:
physics.atm-clus (physics.atm-clus); Nuclear Theory (nucl-th); Atomic Physics (physics.atom-ph)
arXiv:
2605.12315 [pdf]
J.Phys.B·0 citations

Affiliations

first authorsco-authorsvia INSPIRE