1. Rates of neutrino conversion and decay in hot and dense QED plasma - Asida, N.; Niégawa, A.; Ozaki, H.; Kubota, M.
Using a real-time formalism of equilibrium and nonequilibrium quantum-field theory, we derive the reaction-rate formula for neutrino-conversion ($\nu \to \nu'$) process and $\nu \bar{\nu}'$ annihilation process, which take place in a hot and dense QED plasma with background (anti)neutrinos out of equilibrium. Also derived is the formula for the inverse processes to the above ones. Using the hard-thermal-loop resummation scheme, we include the contribution from the coherent processes. The decay/production of a neutrino causes an evolution of its spatial distribution. A scheme for dealing with this evolution is presented. For the case of isotropic neutrino distribution, numerical computation is carried out for the parameter region of type-II super-nova explosion. Defferential...
- 24-mar-2007

2. Time Delay Between Gravitational Waves and Neutrino Burst From a Supernova Explosion: a Test for the Neutrino Mass - Fargion, D.
During Supernova explosions two signals, Gravitational burst wave and Neutrino Burst, of different nature, originated within 0.1 s from thesuper nova explosion will be radiated in the outer space. If the neutrinos (as well as the gravitons) are massless particles, than the original interval (if any) between the two signals will be freezed forever. On the contrary, if the neutrinos have a tiny mass, the time delay will increase during the propagation because of the slower velocity of the neutrinos with respect to the massless gravitons. Therefore, two signals, of different nature, originated within 0.1 s from the super nova explosion will be radiated in the outer space....
- 11-mar-2007