摘要
The in-medium quark condensate is studied with an equivalent quark mass approach that has the advantage of no need for extra assumptions on the current mass derivatives of model parameters with respect to the quark current mass. It is found that the ratio of the quark condensate in a medium to that in a vacuum depends not only on density but also on the finite size. With decreasing volume, it decreases to a minimum, and then saturates at a radius of about 1 fro. The condensate approaches to its bulk value when the volume becomes infinitely large, and it decreases finearly with increasing density if the density is extremely low.
The in-medium quark condensate is studied with an equivalent quark mass approach that has the advantage of no need for extra assumptions on the current mass derivatives of model parameters with respect to the quark current mass. It is found that the ratio of the quark condensate in a medium to that in a vacuum depends not only on density but also on the finite size. With decreasing volume, it decreases to a minimum, and then saturates at a radius of about 1 fro. The condensate approaches to its bulk value when the volume becomes infinitely large, and it decreases finearly with increasing density if the density is extremely low.
基金
Supported by the National Natural Science Foundation of China under Grant No 11135011, the Key Project from Chinese Academy of Sciences under Grant No 12AOA0012, and the UCAS-SINAP Cooperative Project under Grant No Y1530111A8.
