Nuclear Theory·nucl-th

Monday·December 5, 2022

7 papers—5 primary·2 cross-listed

01
Far-from-equilibrium slow modes and momentum anisotropy in expanding plasma
Jasmine Brewer🇨🇭 · Weiyao Ke🇺🇸 · Li Yan🇨🇳 · Yi Yin🇨🇳
The momentum distribution of particle production in heavy-ion collisions encodes information about thermalization processes in the early-stage quark-gluon plasma. We use kinetic theory to study the far-from-equilibrium evolution of an expanding plasma with an anisotropic momentum-space distribution. We identify slow and fast degrees of freedom in the far-from-equilibrium plasma from the evolution of moments of this distribution. At late times, the slow modes correspond to hydrodynamic degrees of freedom and are naturally gapped from the fast modes by the inverse of the relaxation time, $τ_{R}^{- 1}$ . At early times, however, there are an infinite number of slow modes with a gap inversely proportional to time, $τ^{- 1}$ . From the evolution of the slow modes we generalize the paradigm of the far-from-equilibrium attractor to vector and tensor components of the energy-momentum tensor, and even to higher moments of the distribution function that are not part of the hydrodynamic evolution. We predict that initial-state momentum anisotropy decays slowly in the far-from-equilibrium phase and may persist until the relaxation time.
nucl-thPRD(2024)·14 citations
02
Microscopic study of the deformed neutron halo of 31Ne
R.Takatsu · Y. Suzuki · W. Horiuchi · M. Kimura
The properties of the deformed halo of 31Ne were discussed using the antisymmetrized molecular dynamics plus resonating group method (AMD+RGM). The AMD+RGM calculations describe a large neutron radius for the ground state and reveal that the ground state is dominated by core-excited components. The resonant states were also investigated by applying the analytical continuation of the coupling constant. It was found that the first excited state (the 5/2- state) is also dominated by core-excited components and has a small decay width, whereas the second excited state (the 7/2- state) is dominated by the valence neutron in the $f$ -wave coupled to the ground state of 30Ne.
nucl-thnucl-exPRC(2023)·12 citations
03
On the strong local potential limit
K. Murulane🇿🇦 · S. Karataglidis🇿🇦 · B. G. Giraud🇫🇷
Finite, bound, many-body systems, where the interaction operator, $V = \sum v_{ij}$ , is local and happens to strongly dominate the kinetic energy operator, $T = \sum t_{i}$ , display a classical limit from diagonalizing $V$ alone, hence a clear picture of interparticle correlations, such as steric blocking emerges. This limit exhibits intrinsic symmetries and also fluctuations from mass formulae. The present work investigates how such emergent symmetries and fluctuations might be extrapolated to physical situations where $T$ is reinstated.
nucl-thIJMPE(2023)·0 citations
04
Heavy Baryons in Compact Stars
Armen Sedrakian🇩🇪 · Jia-Jie Li🇨🇳 · Fridolin Weber🇺🇸
We review the physics of hyperons and $Δ$ -resonances in dense matter in compact stars. The covariant density functional approach to the equation of state and composition of dense nuclear matter in the mean-field Hartree and Hartree-Fock approximation is presented, with regimes covering cold $β$ -equilibrated matter, hot and dense matter with and without neutrinos relevant for the description of supernovas and binary neutron star mergers, as well as dilute expanding nuclear matter in collision experiments. We discuss the static properties of compact stars with hyperons and $Δ$ -resonances in light of constraints placed in recent years by the multimessenger astrophysics of compact stars on the compact stars' masses, radii, and tidal deformabilities. The effects of kaon condensation and strong magnetic fields on the composition of hypernuclear stars are also discussed. The properties of rapidly rotating compact hypernuclear stars are discussed and confronted with the observations of 2.5-2.8 solar mass compact objects in gravitational wave events. We further discuss the cooling of hypernuclear stars, the neutrino emission reactions, hyperonic pairing, and the mass hierarchy in the cooling curves that arises due to the onset of hyperons. The effects of hyperons and $Δ$ -resonances on the equation of state of hot nuclear matter in the dense regime, relevant for the transient astrophysical event and in the dilute regime relevant to the collider physics is discussed. The review closes with a discussion of universal relations among the integral parameters of hot and cold hypernuclear stars and their implications for the analysis of binary neutron star merger events.
nucl-thastro-ph.HEastro-ph.SRPPNP(2023)·106 citations
05
Hybrid stars with large strange quark cores
Márcio Ferreira🇵🇹 · Renan Câmara Pereira🇵🇹 · Constança Providência🇵🇹
The possible existence of hybrid stars is studied using several multi-quark interaction channels. The hadronic phase consists of an equation of state (EoS) with presently accepted nuclear matter properties and the quark model is constrained by the vacuum properties of several light mesons. The dependence of several NS properties on the different quark interactions is analyzed. We show that the present constraints from neutron star observations allow for the existence of hybrid stars with large strangeness content and large quark cores.
nucl-thastro-ph.HEhep-phEPJ Web Conf.(2022)·1 citation

Affiliations

first authorsco-authorsvia INSPIRE

Far-from-equilibrium slow modes and momentum anisotropy in expanding plasma

Microscopic study of the deformed neutron halo of 31Ne

On the strong local potential limit

Heavy Baryons in Compact Stars

Hybrid stars with large strange quark cores

Affiliations