Energy release due to antineutrino untrapping and diquark condensation in hot quark star evolution

We study the consequences of antineutrino trapping in hot quark matter for quark star configurations with possible diquark condensation. Due to the conditions of charge neutrality and β-equilibrium the flavor asymmetry increases with the number density of trapped antineutrinos. Above a critical value of the antineutrino chemical potential of 30 MeV diquark condensation is inhibited at low densities and a two-phase structure emerges: a superconducting quark matter core surrounded by a shell of normal quark matter. When the quark star cools down below a temperature T ∼ 1 MeV, the mean free path of antineutrinos becomes larger than the thickness of the normal quark matter shell so that they get untrapped within a sudden process. By comparing the masses of configurations with the same baryon number we estimate that the release of energy due to the antineutrino untrapping transition can be in the range of 10 ÷ 10 erg.