2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/81634After giving brief discussions on the chiral condensate in hot and/or dense hadronic matter and the significance of the $σ$ 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 $σ$ meson and for exploring the possible restoration of chiral symmetry in nuclear medium.Invited talk presented at International Workshop on Physics with GeV Electrons and Gamma-rays, Laboratory of Nuclear Science, Tohoku University, Feb. 13 - 15, 2001Nuclear Theorytext