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. 
Abhijit Bhattacharyya, Sanjay K. Ghosh and Sibaji Raha