  We investigate the effect of neutrino trapping on kaon condensation process
and Equation of State (EOS) in a newly formed neutron star which is less than
several seconds old. Using nonlinear relativistic mean field model, we find
that the presence of neutrino shifts the threshold for kaon condensation and
muon production to much higher density. We also studied the energy density and
pressure of the syst under trapped neutrino condition and found that it
stiffens the EOS of the system which may be responsible for the delayed
exploision mechanism of supernovae.
