K̄ 0 condensation in neutron stars

We investigate the condensation of charged K meson and neutral K̄ meson in dense neutron star matter. Calculations are performed in relativistic mean field models in which both the baryon-baryon and (anti)kaon-baryon interactions are mediated by meson exchange. It is found that K̄ condensation is quite sensitive to the antikaon optical potential and depends more strongly on the nucleonic equation of state. For moderate values of antikaon potential and a rather stiff equation of state, a significant region of maximum mass star will contain K̄ meson. The critical density of K̄ condensation is always higher than that of K condensation. With the appearance of K and K̄ condensates, pairs of p−K and n− K̄ are produced with equal proportion leading to a perfectly symmetric matter of nucleons and antikaons in neutron stars. Along with K condensate, K̄ condensate makes the equation of state much softer resulting in smaller maximum mass stars compared to the case without any condensate.