BOUNDS ON THE NEUTRINO MAGNETIC-MOMENT FROM SN-1987-A

We examine the emission of wrong helicity neutrinos from SN 1987 A due to neutrino magnetic moment (mu(upsilon)). We consider the case when the core of nascent neutron star is on the verge of pion condensation. The relevant processes are the p+pi(-)-->n+upsilon(L,R)($) over bar upsilon(L,R) and pi upsilon(L)(($) over bar upsilon(R))-->pi upsilon(R)(($) over bar upsilon(L)). We have also studied the case where the core is assumed to have undergone a phase transition to quark matter. The important process here is q+upsilon(L) (($) over bar upsilon(R))-->q+upsilon(R) (($) over bar upsilon(L)). By imposing a bound on upsilon(R) luminosity, we get a limit on mu(upsilon)less than or similar to(0.3-0.05)X10(-12) mu(B) depending on the temperature and composition of the core.