THERMAL DILEPTON PRODUCTION FROM DROPPING ρ IN THE VECTOR MANIFESTATION

Abstract

We study the pion electromagnetic form factor and the dilepton production rate in hot matter based on the vector manifestation (VM) of chiral symmetry in which the massless vector meson becomes the chiral partner of the pion, giving a theoretical framework of the dropping ρ à la Brown–Rho scaling. The VM predicts a strong violation of the vector dominance (VD) near the phase transition point associated with the dropping ρ. We present the effect of the VD violation to the dilepton production rate and make a comparison to the one predicted by assuming the VD together with the dropping ρ.