Antikaon condensation and the metastability of protoneutron stars - art. no. 035802

We investigate the condensation of (K) over bar (0) mesons along with K- co ndensation in neutrino-trapped matter with and without hyperons. Calculatio ns are performed in the relativistic mean field models in which both the ba ryon-baryon and (anti)kaon-baryon interactions are mediated by meson exchan ge. In the neutrino-trapped matter relevant to protoneutron stars, the crit ical density of K- condensation is shifted considerably to higher density w hereas that of (K) over bar (0) condensation is shifted slightly to higher density with respect to that of the neutrino-free case. The onset of K- con densation always occurs earlier than that of (K) over bar (0) condensation. A significant region of maximum mass protoneutron stars is found to contai n (K) over bar (0) condensate for larger values of the antikaon potential. With the appearance of (K) over bar (0) condensation. there is a region of symmetric nuclear matter in the inner core of a protoneutron star. We note that the gross properties of the protoneutron stars are significantly affec ted by the antikaon condensation for larger values of the antikaon potentia l. It is found that the maximum mass of a protoneutron star containing K- a nd (K) over bar (0) condensate is greater than that of the corresponding ne utron star. We reexamine the implication of this scenario in the context of the metastability of protoneutron stars and their evolution to low mass bl ack holes.