nucl-th digest · Oct 18, 2021

Hot Quark Matter with Neutrino Confinement in the Framework of the Local Nambu--Jona-Lasinio SU(3) Model

The thermodynamic characteristics of hot

β

-equilibrium electrically neutral three-flavor quark matter at neutrino confinement are investigated. For the thermodynamic description of such a quark-lepton system, the local SU (3) Nambu--Jona-Lasinio (NJL) model is used, in which also takes into account the 't Hooft interaction, leading to the quark flavor mixing effect. The energy density

ε

and pressure

P

of quark matter are numerically determined for different values of the baryon number density in the range

n_{B} \in [0.02 \div 1.8]

^{- 3}

and temperatures in the range

T \in [0 \div 100]

MeV. The results obtained are compared with the results of cold quark matter calculated within the framework of the same model, but under the assumption that all neutrinos have already left the system. The dependence of the contribution of individual quark flavors to the baryon charge of the system at different temperatures is discussed. Both isothermal and adiabatic speeds of sound in hot quark matter are determined depending on the baryon number density.

nucl-thAstrophysics(2021)·4 citations

Unified picture of nucleon pairs playing leading roles in nuclear collectivity

Dennis Bonatsos · Andriana Martinou · I.E. Assimakis · S.K. Peroulis · S. Sarantopoulou · N. Minkov

Proxy-SU(3) symmetry is an approximation scheme extending the Elliott SU(3) algebra of the sd shell to heavier shells. When introduced in 2017, the approximation had been justified by calculations carried out within the Nilsson model, with nucleon pairs differing by $Δ K [Δ N Δ n_{z} ΔΛ] = 0 [110]$ in the Nilsson quantum numbers playing a major role in the approximation. Recently our group managed to map the cartesian basis of the Elliott SU(3) model onto the spherical shell model basis, fully clarifying the approximations used within the proxy-SU(3) scheme and paving the way for using the proxy-SU(3) approximation in shell model calculations for heavy nuclei. As a by-product, the relation of the 0[110] Nilsson pairs used in proxy-SU(3) to the earlier used de Shalit-Goldhaber pairs $∣Δ n Δ l Δ j Δ m_{j} ⟩ = ∣0110 ⟩$ in spherical shell model notation is clarified, while the Federman-Pittel (FP) pairs known to play a major role at the onset of deformation are identified as $∣0010 ⟩$ pairs, and the FP pairs further increasing the deformation after its onset are found to be $∣0110 ⟩$ pairs, i.e. identical to the de-Shalit-Goldhaber pairs. The connection between the proxy-SU(3) scheme and the spherical shell model has also been worked out in the original framework of the Nilsson model, with identical results.

nucl-thBulg.J.Phys.(2021)·2 citations

Monday·October 18, 2021

Hot Quark Matter with Neutrino Confinement in the Framework of the Local Nambu--Jona-Lasinio SU(3) Model

Unified picture of nucleon pairs playing leading roles in nuclear collectivity

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