出版社：SISSA, Scuola Internazionale Superiore di Studi Avanzati
摘要：Meson properties at nite temperature and density are studied in lattice QCD simulations with two-avor Wilson fermions. For this purpose, we investigate screening masses of mesons in pseudo-scalar (PS) and vector (V) channels. The simulations are performed on 163 4 lattice along the lines of constant physics at mPS=mVjT=0 = 0:65 and 0.80, where mPS=mVjT=0 is a ratio of meson masses in PS and V channels at T = 0. A temperature range is T=Tpc = (0:84:0), where Tpc is the pseudo-critical temperature. We nd that the temperature dependence of the screening masses normalized by temperature, M0=T, shows notable structure around Tpc, and approach 2p at high temperature in both channels, which is consistent with twice the thermal mass of a free quark in high temperature limit. The screening masses at low density are also investigated by using the Taylor expansion method with respect to the quark chemical potential. We nd that the expansion coefcients in the leading order become positive in the temperature range, and thermal and density effect on the meson screening-masses becomes apparent in the quark-gluon plasma phase. The meson screening-masses are also compared with the gluon (Debye) screening masses at nite temperature and density.
