0000000001189298
AUTHOR
Armando Perez
Pair production of helicity-flipped neutrinos in supernovae.
The emissivity was calculated for the pair production of helicity-flipped neutrinos, in a way that can be used in supernova calculations. Also presented are simple estimates which show that such process can act as an efficient energy-loss mechanism in the shocked supernova core, and this fact is used to extract neutrino mass limits from SN 1987A neutrino observations.
Screening effects in Relativistic Models of Dense Matter at Finite Temperature
We investigate screening effects of the medium on the potential interaction between two static 'charges' for different models of dense plasmas in the one-boson exchange approximation. The potential can exhibit an oscillatory behavior, which is related to the analytic structure of the corresponding boson propagators in the complex $q$-plane. We have first revisited the one-pion exchange in a nuclear medium. In addition to Friedel oscillations, which are associated to branch cuts in the $q$-plane, there appears another oscillatory component, which arises from a pole on the pion propagator. This pole is located appart from the axes, giving rise to an oscillating Yukawa-like potential. Therefor…