The sigma meson and chiral restoration in nuclear medium

Abstract

After giving brief discussions on the chiral condensate in hot and/or dense hadronic matter and the significance of the $\sigma$ meson in QCD, we discuss the importance of experiments using nuclear targets including ones with electro-magnetic probes for obtaining clearer confirmation of the existence of the $\sigma$ meson and for exploring the possible restoration of chiral symmetry in nuclear medium.

Comments: Invited talk presented at International Workshop on Physics with GeV Electrons and Gamma-rays, Laboratory of Nuclear Science, Tohoku University, Feb. 13 - 15, 2001