Energy Release due to Antineutrino Untrapping from Hot Quark Stars

An equation of state for 2-flavor quark matter (QM) with diquark condensation under the conditions for compact stars -β-equilibrium, charge and color neutrality- is presented. Trapped antineutrinos prevent the formation of the diquark condensate at moderate densities above a critical value of the antineutrino chemical potential μ ^c_{bar {ν e}}. The following consequences are presented: 1) The star develops a 2-phase structure (μ _{bar {ν e}} >= μ ^c_{bar {ν e})}: a color superconducting QM core and a normal QM shell. 2)During the cooling, when the temperature is small enough (T < 1 MeV) the antineutrino mean free path becomes larger than the thickness of the normal QM shell and the antineutrinos get untrapped in a sudden burst. The energy release is estimated as ≃ 10⁵² erg and an antineutrino pulse is expected to be observed.