Antikaon condensation in neutron stars

We investigate the condensation of charged K- meson and neutral K-0 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 K-0 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 K-0 The critical density of K-0 condensation is always higher than that of K- condensation. With the appearance of K- and K-0 condensates, pairs of p - K- and n - K-0 are produced with equal proportion leading to a perfectly symmetric matter of nucleons and antikaons in neutron stars. Along with K- condensate, K-0 condensate makes the equation of state much softer resulting in smaller maximum mass stars compared to the case without any condensate. (C) 2000 Elsevier Science B.V. All rights reserved.