Nuclear Theory·nucl-th

Wednesday·May 13, 2026

13 papers—5 primary·8 cross-listed

01
The mean-field theory of superfluid-superconducting vortex states in the outer core of neutron stars
Dmitry Kobyakov
Purpose: Characterize superfluid-superconducting vortex states at arbitrary pressures with $T_{c p} \neq = T_{c n}$ , assuming both proton and neutron mean-fields are formed by spin-0 Cooper pairs. Method: The existing mean-field theory is extended to account for $T_{c p} \neq = T_{c n}$ . The pressure dependence of the pairing gap energy $Δ_{α 0}$ is quantitatively established on the basis of the effective chiral field theory. To link $T_{c α}$ with $Δ_{α 0}$ , I use the weak-coupling result $T_{c α} \approx 0.57 Δ_{α 0}$ . A quadratic scaled-temperature ( $T / T_{c p}$ ) dependence of the thermodynamic magnetic field is postulated in analogy with pure superconductors. The $T / T_{c α}$ -dependence of the gap $Δ_{α T}$ is inferred from the many-body approximations for the pure neutron matter. Results: An empirical $T / T_{c α}$ -dependence for the mean-field is constructed to account for the interplay between the condensation and the magnetic energies. The superfluid entrainment is found to increase the size of the vortex core and to decrease the effective magnetic penetration depth. The size of the neutron vortex core is found to be larger than the magnetic penetration depth in the outer core. Conclusions: The usual approximation of infinitely thin vortex line (the London's approximation) for the neutron vortex is found to be irrelevant in the entire outer core and for the proton vortex is found to be limited to vicinity of the crust-core transition. The developed mean-field theory paves the way to study the vortex microscopic structure, the angular momentum, the magnetization and the vortex-fluxtube interaction energy.
nucl-thastro-ph.SRcond-mat.supr-con0 citations
02
Rigorous proof of the Strutinsky energy theorem and foundations of nuclear density functional theory
Chong Qi
We have derived a rigorous theoretical proof of the Strutinsky energy theorem. This proof not only provides a proper interpretation of the shell-correction decomposition, resolving decades of confusion, but also lays a foundation for constructing nuclear density functionals.
nucl-th0 citations
03
Freeze-out model of light nuclei formation in heavy-ion collision transport
Oleh Savchuk🇺🇸 · Pawel Danielewicz🇺🇸 · William Lynch🇺🇸 · Jérôme Margueron🇺🇸
Cluster production plays an important role in heavy-ion collisions at intermediate beam energies, where light nuclei contribute substantially to final-state yields and to other observables that are used to infer the nuclear equation of state. In this letter, we propose a new approach for clustering that combines dynamical transport and thermal cluster production for mid-rapidity particles. The resulting hybrid coarse-graining model matches nucleon and light-cluster descriptions at freeze-out while properly accounting for thermal non-uniformity and collective transport in the hot, strongly interacting systems created in heavy-ion collisions. To illustrate the capabilities of this model, yields at 4~fm impact parameter, spectra and elliptic flows at 7.4~fm ( $20 - 30%$ centrality) are predicted at mid-rapidity for semi-peripheral Au $+$ Au collisions at an incident energy of $E_{lab} = 1.23 A GeV$ .
nucl-th0 citations
04
Ab initio calculation of symmetry-breaking observables
A Belley · B. Romeo · J. Engel · D. Kekejian · T. Miyagi · S. Foster · P. Navratil · B. C. He · S. R. Stroberg · J. D. Holt · R. F. Garcia Ruiz
Symmetry-violating observables such as the nuclear anapole and Schiff moments provide sensitive probes of the fundamental symmetries of nature and physics beyond the Standard Model. Their interpretation has been hindered, however, by the lack of ab initio nuclear structure calculations in the medium-mass and heavy nuclei of interest to experimentalists. To provide them, we introduce a new version of the in-medium similarity renormalization group (IMSRG) designed to target parity-violating operators. By generalizing the IMSRG flow equations to evolve the weak symmetry-breaking Hamiltonian - and the anapole or Schiff operators - alongside the strong nuclear Hamiltonian, we construct a systematically improvable framework for computing these parity-violating moments. We benchmark the method against the no-core shell model in light nuclei and obtain the first ab initio predictions of the anapole moment in $^{29}$ Si and the Schiff moments in $^{129}$ Xe. These heavier systems are of direct experimental interest.
nucl-thnucl-ex4 citations
05
Mass radius and D-term of atomic nuclei in relativistic mean field theory
Yoshitaka Hatta · Tomohiro Oishi · Makoto Oka
Based on relativistic mean field theory for atomic nuclei, we compute the mass radius and other radii associated with the energy momentum tensor for dozens of spin-0 nuclei across the nuclear chart. We also compute the D-term of these nuclei, the forward limit of the gravitational form factor $D (t = 0) = D$ . The dependence on the neutron number $N$ is systematically studied for calcium (Ca), nickel (Ni), zirconium (Zr), tin (Sn) and lead (Pb) isotopes. Remarkably, $∣ D ∣$ does not monotonically increase with $N$ . Instead, it exhibits local maxima and minima when $N$ equals a magic number and even a sub-magic number. This results in characteristic kinks in the mass, scalar, tensor and shear radii of these isotopes. Our work for the first time elucidates the strong sensitivity of the various mechanical properties of nuclei to the nuclear shell structure.
nucl-thhep-phPRC(2026)·1 citation
06
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.
↳ hep-phnucl-th3 citations
07
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.
↳ quant-phcond-mat.supr-connucl-th0 citations
08
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.
↳ nucl-exnucl-thPRC(2026)·0 citations
09
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.
↳ hep-phnucl-thNPB 1028, 117510 (2026)·0 citations
10
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.
↳ hep-phnucl-th0 citations
11
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.
↳ hep-phhep-exnucl-exnucl-th0 citations
12
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.
↳ hep-thnucl-th2 citations
13
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.
↳ physics.atm-clusnucl-thphysics.atom-phJ.Phys.B·0 citations

Affiliations

first authorsco-authorsvia INSPIRE