Effects ofN¯Npolarization on vector meson masses at finite temperature

Abstract
Effects of N¯N polarization on vector meson (ρ and ω) masses at finite temperature are studied. Including a reduced nucleon mass in a hot matter, we find that the reduction of vector meson masses due to the vacuum effect is larger than the increase of their masses from interactions with nucleons and pions in the hot matter. The vector meson masses at finite temperature thus decrease with temperature.