  We examine the impact of electromagnetic properties of neutrinos on the
annihilation of relic neutrinos with ultra high energy cosmic neutrinos for the
$\nu \bar{\nu}\to \gamma\gamma$ process. For this process, photon-neutrino
decoupling temperature is calculated via effective lagrangian model beyond the
standard model. We find that photon-neutrino decoupling temperature can be
importantly reduced below the QCD phase transition with the model independent
analysis defining electromagnetic properties of neutrinos.
