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
05
Some Conceptual Aspects of Operator Design for Quantum Simulations of Non-Abelian Lattice Gauge Theories
Anthony Ciavarella🇺🇸 · Natalie Klco🇺🇸 · Martin J. Savage🇺🇸
In the Kogut-Susskind formulation of lattice gauge theories, a set of quantum numbers resides at the ends of each link to characterize the vertex-local gauge field. We discuss the role of these quantum numbers in propagating correlations and supporting entanglement that ensures each vertex remains gauge invariant, despite time evolution induced by operators with (only) partial access to each vertex Hilbert space. Applied to recent proposals for eliminating vertex-local Hilbert spaces in quantum simulation, we describe how the required entanglement is generated via delocalization of the time evolution operator with nearest-neighbor controls. These hybridizations, organized with qudits or qubits, exchange classical operator preprocessing for reductions in quantum resource requirements that extend throughout the lattice volume.
↳ quant-phhep-lathep-phnucl-th32 citations
06
Composition of low-lying $J = \frac{3}{2}^{\pm} Δ$ -baryons
Langtian Liu🇨🇳 · Chen Chen🇨🇳 · Ya Lu🇨🇳 · Craig D. Roberts🇨🇳 · Jorge Segovia🇨🇳
A Poincaré-covariant quark+diquark Faddeev equation is used to develop insights into the structure of the four lightest $(I, J^{P} = \frac{3}{2}, \frac{3}{2}^{\pm})$ baryon multiplets. Whilst these systems can contain isovector-axialvector and isovector-vector diquarks, one may neglect the latter and still arrive at a reliable description. The $(\frac{3}{2}, \frac{3}{2}^{+})$ states are the simpler systems, with features that bear some resemblance to quark model pictures, \emph{e.g}., their most prominent rest-frame orbital angular momentum component is $S$ -wave and the $Δ (1600) \frac{3}{2}^{+}$ may reasonably be viewed as a radial excitation of the $Δ (1232) \frac{3}{2}^{+}$ . The $(\frac{3}{2}, \frac{3}{2}^{-})$ states are more complex: the $Δ (1940) \frac{3}{2}^{-}$ expresses little of the character of a radial excitation of the $Δ (1700) \frac{3}{2}^{-}$ ; and whilst the rest-frame wave function of the latter is predominantly $P$ -wave, the leading piece in the $Δ (1940) \frac{3}{2}^{-}$ wave function is $S$ -wave, in conflict with quark model expectations. Experiments that can test these predictions, such as large momentum transfer resonance electroexcitation, may shed light on the nature of emergent hadron mass.
↳ hep-phhep-exhep-latnucl-ex+1PRD(2022)·33 citations
07
Neutrinoless Double-Beta Decay: A Roadmap for Matching Theory to Experiment
Vincenzo Cirigliano🇺🇸 · Zohreh Davoudi🇺🇸 · Wouter Dekens🇺🇸 · Jordy de Vries🇳🇱 · Jonathan Engel🇺🇸 · Xu Feng🇨🇳 · Julia Gehrlein🇺🇸 · Michael L. Graesser🇺🇸 · Lukáš Gráf🇺🇸 · Heiko Hergert🇺🇸 · Luchang Jin🇺🇸 · Emanuele Mereghetti🇺🇸 and 7 other authors
The observation of neutrino oscillations and hence non-zero neutrino masses provided a milestone in the search for physics beyond the Standard Model. But even though we now know that neutrinos are massive, the nature of neutrino masses, i.e., whether they are Dirac or Majorana, remains an open question. A smoking-gun signature of Majorana neutrinos is the observation of neutrinoless double-beta decay, a process that violates the lepton-number conservation of the Standard Model. This white paper focuses on the theoretical aspects of the neutrinoless double-beta decay program and lays out a roadmap for future developments. The roadmap is a multi-scale path starting from high-energy models of neutrinoless double-beta decay all the way to the low-energy nuclear many-body problem that needs to be solved to supplement measurements of the decay rate. The path goes through a systematic effective-field-theory description of the underlying processes at various scales and needs to be supplemented by lattice quantum chromodynamics input. The white paper also discusses the interplay between neutrinoless double-beta decay, experiments at the Large Hadron Collider and results from astrophysics and cosmology in probing simplified models of lepton-number violation at the TeV scale, and the generation of the matter-antimatter asymmetry via leptogenesis. This white paper is prepared for the topical groups TF11 (Theory of Neutrino Physics), TF05 (Lattice Gauge Theory), RF04 (Baryon and Lepton Number Violating Processes), NF03 (Beyond the Standard Model) and NF05 (Neutrino Properties) within the Theory Frontier, Rare Processes and Precision Frontier, and Neutrino Physics Frontier of the U.S. Community Study on the Future of Particle Physics (Snowmass 2021).
↳ hep-phhep-exhep-latnucl-ex+196 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

Some Conceptual Aspects of Operator Design for Quantum Simulations of Non-Abelian Lattice Gauge Theories

Composition of low-lying J=23​±Δ-baryons

Neutrinoless Double-Beta Decay: A Roadmap for Matching Theory to Experiment

Affiliations

Composition of low-lying $J = \frac{3}{2}^{\pm} Δ$ -baryons