Nuclear Theory·nucl-th

Thursday·March 24, 2022

7 papers—4 primary·3 cross-listed

01
Entanglement entropy, single-particle occupation probabilities, and short-range correlations
Aurel Bulgac
For quantum many-body systems with short-range correlations (SRCs), the intimate relationship between their magnitude, the behavior of the single-particle occupation probabilities at momenta larger than the Fermi momentum, and the entanglement entropy is a new qualitative aspect not studied and exploited yet. A large body of recent condensed matter studies indicate that the time evolution of the entanglement entropy describes the non-equilibrium dynamics of isolated and strongly interacting many-body systems, in a manner similar to the Boltzmann entropy, which is strictly defined for dilute and weakly interacting many-body systems. Both theoretical and experimental studies in nuclei and cold atomic gases have shown that the fermion momentum distribution has a generic behavior $n (k) = C / k^{4}$ at momenta larger than the Fermi momentum, due to the presence of SRCs, with approximately 20\% of the particles having momenta larger than the Fermi momentum. The presence of the long momentum tails in the presence of SRCs changes the textbook relation between the single-particle kinetic energy and occupation probabilities, $n_{mf} (k) = 1 / {1 + exp β [ϵ (k) - μ]}$ for momenta very different form the Fermi momentum, particularly for dynamics processes. SRCs induced high-momentum tails of the single-particle occupation probabilities increase the entanglement entropy of fermionic systems, which in its turn affects the dynamics of many nuclear reactions, such as heavy-ion collisions and nuclear fission.
nucl-thcond-mat.quant-gasPRC(2023)·41 citations
02
The SuSAv2 model for inelastic neutrino-nucleus scattering
J. Gonzalez-Rosa🇪🇸 · G. D. Megias🇪🇸 · J. A. Caballero🇪🇸 · M. B. Barbaro🇮🇹
The susperscaling model SuSAv2, already available for charged-current neutrino-nucleus cross sections in the quasielastic region, is extended to the full inelastic regime. In the model the resonance production and deep inelastic reactions are described through the extension to the neutrino sector of the SuSAv2 inelastic model developed for ( $e, e^{'}$ ) reactions, which combines phenomenological structure functions with a nuclear scaling function. This work also compares two different descriptions of the $Δ$ resonance region, one based on a global scaling function for the full inelastic spectrum and the other on a semi-phenomenological $Δ$ scaling function extracted from ( $e, e^{'}$ ) data for this specific region and updated with respect to previous work. The results of the model are tested against ( $e, e^{'}$ ) data on $^{12}$ C, $^{16}$ O, $^{40}$ Ca and $^{40}$ Ar and applied to the study of the charged current inclusive neutrino cross-section on $^{12}$ C and $^{40}$ Ar measured by the T2K, MicroBooNE, ArgoNEUT and MINERvA experiments, thus covering several kinematical regions.
nucl-thhep-phPRD(2022)·17 citations
03
The hyperonic star in relativistic mean-field model
Kaixuan Huang🇨🇳 · Jinniu Hu🇨🇳 · Ying Zhang🇨🇳 · Hong Shen🇨🇳
The neutron star as a supernova remnant is attracting high attention recently due to the gravitation wave detection and precise measurements about its mass and radius. In the inner core region of the neutron star, the strangeness degrees of freedom, such as the hyperons, can be present, which is also named as a hyperonic star. In this work, the neutron star consisting of nucleons and leptons, and the hyperonic star including the hyperons will be reviewed in the framework of the relativistic mean-field (RMF) model. The popular non-linear and density-dependent RMF parametrizations in the market will be adopted to investigate the role of strangeness baryons in a hyperonic star on its mass, radius, tidal deformability, and other properties. Finally, the magnitudes of the coupling strengths between mesons and hyperons also will be discussed, which can generate the massive hyperonic star with present RMF parameter sets, when the vector coupling constants are strong.
nucl-thNucl.Phys.Rev.(2022)·16 citations
04
Inverse-Reynolds-Dominance approach to transient fluid dynamics
David Wagner · Andrea Palermo · Victor E. Ambruş
We consider the evolution equations for the bulk viscous pressure, diffusion current and shear tensor derived within second-order relativistic dissipative hydrodynamics from kinetic theory. By matching the higher order moments directly to the dissipative quantities, all terms which are of second order in the Knudsen number Kn vanish, leaving only terms of order $O (Re^{- 1} Kn)$ and $O (Re^{- 2})$ in the relaxation equations, where $Re^{- 1}$ is the inverse Reynolds number. We therefore refer to this scheme as the Inverse-Reynolds-Dominance (IReD) approach. The remaining (non-vanishing) transport coefficients can be obtained exclusively in terms of the inverse of the collision matrix. This procedure fixes unambiguously the relaxation times of the dissipative quantities, which are no longer related to the eigenvalues of the inverse of the collision matrix. In particular, we find that the relaxation times corresponding to higher-order moments grow as their order increases, thereby contradicting the \textit{separation of scales} paradigm. The formal (up to second order) equivalence with the standard DNMR approach is proven and the connection between the IReD transport coefficients and the usual DNMR ones is established.
nucl-thphysics.flu-dynPRD(2022)·33 citations

Affiliations

first authorsco-authorsvia INSPIRE

Entanglement entropy, single-particle occupation probabilities, and short-range correlations

The SuSAv2 model for inelastic neutrino-nucleus scattering

The hyperonic star in relativistic mean-field model

Inverse-Reynolds-Dominance approach to transient fluid dynamics

Affiliations