QCD phase transition in rotaing neutron star, Neutrino beaming and Gamma-ray bursters

We have studied the emission of neutrinos from a rotating hybrid star. We find that the emission is predominantly confined to a very small angle, provided the core of the star is in a mixed phase of quarks and hadrons and the size of such a mixed phase is small. Annihilation of neutrinos to produce gamma rays has been discussed. The estimated duration of the burst is found to be within the observational range.Comment: Modified manuscript with 9 pages including 3 ps figures, Accepted for publication in Phys. Lett.