Equation of State for Hot Quark Matter with Neutrino Confinement

The equation of state and composition of hot strange quark matter that is opaque to neutrinos are determined. This study is based on the MIT quark bag model. Three different variants of the lepton population in hot quark matter are considered. In the first, only e^–, e⁺, ν_e, and ${\overline{\upnu}}_e$ leptons are present in the material. In the second, μ^–, μ⁺, ν_μ, and ${\overline{\upnu}}_{\upmu}$ are added to these leptons. And in the third, τ^– neutrinos and τ⁺ antineutrinos are also present and the phenomenon of neutrino oscillations is taken into account. Numerical calculations are done for different temperatures and lepton charge densities. It is shown that when neutrinos exist in hot quark matter (T~1012 K) the number of u quarks is 24-33% and 37-42% greater than the number of d and s quarks, respectively, depending on the baryon charge concentration. When neutrino oscillations are included, these parameters go to 19-27% and 30-37%. When there are no neutrinos, on the other hand, the number of d quarks is less than the number of u quarks by 2-8%. It is shown that for a fixed baryon charge concentration, the pressure of the quark matter depends strongly on temperature. This dependence is especially strong at comparatively low densities. As opposed to this, the pressure has a weak temperature dependence for a fixed energy density.