Revisiting the phase diagram of the three-flavor quark system in the Nambu-Jona-Lasinio model

We propose the 2 + 1 flavor chiral susceptibility criterion to identify the chiral phase transition of the 2 + 1 flavor quark system and take it to determine the phase boundary and the critical end point (CEP) in the Nambu-Jona-Lasinio model. We give explicitly the phase diagram of the 2 + 1 flavor quark system in terms of the temperature, quark chemical potential and strange quark mass and that in terms of the temperature, quark chemical potential, and flavor-mixing interaction strength. We locate the CEP of the 2 + 1 quark system with physical masses at (mu(E), T-E) = (316.2 MeV, 68.1 MeV). We show that increasing the mass of the strange quark lowers the temperature and enhances the chemical potential of the CEP if the mass is not quite large, and there exists a critical flavor-mixing interaction strength (K Lambda(5))(c) approximate to 6.05 for the crossover to turn into a first order phase transition. Increasing the flavor-mixing strength beyond the critical one induces the temperature of the CEP to increase drastically and raises slightly at first and then descends the chemical potential.http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000322084100004&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=8e1609b174ce4e31116a60747a720701Astronomy & AstrophysicsPhysics, Particles & FieldsSCI(E)5ARTICLE1null8