NEUTRINO EMISSIVITY OF AN ULTRARELATIVISTIC PLASMA FROM POSITRON AND PLASMINO ANNIHILATION

In an ultrarelativistic electron plasma, the electron acquires a large effective mass and an extra propagating mode called the plasmino. The neutrino emissivity from the annihilation process is calculated taking these plasma effects into account. When the temperature is sufficiently small compared to the electron Fermi energy, the emissivity from the annihilation of the electron with the positron plasmino exceeds that from the annihilation with the positron. Unless neutrinos become degenerate, the effect of the plasmino becomes significant only when the total annihilation contribution to the emissivity is negligible compared to that from photon and plasmon decay.