Antikaon Condensation and In-medium Kaon and AntikaonProduction in Protoneutron Stars

Abstract

Antikaon condensation and kaon and antikaon production inprotoneutron stars are investigated in a chiral hadronic model(also referred to as the FST model in this paper). The effects ofneutrino trapping on protoneutron stars are analyzedsystematically. It is shown that neutrino trapping makes the criticaldensity of K− condensation delay to higher density and K̄0condensation not occur. The equation of state (EOS) of (proto)neutron starmatter with neutrino trapping is stiffer than that without neutrino trapping.As a result, the maximum masses of (proto)neutron stars with neutrinotrapping are larger than those without neutrino trapping. If hyperonsare taken into account, antikaon does not form a condensate in(proto)neutron stars. Meanwhile, the corresponding EOS becomes much softer,and the maximum masses of (proto)neutron stars are smaller than thosewithout hyprons. Finally, our results illustrate that the Q values for K+and K− production in (proto)neutron stars are not sensitive to neutrinotrapping and inclusion of hyperons.