Quenching of gA in the nuclear medium

The numerical values of gA are evaluated using quantum-chromodynamic sum rules. The nuclear medium effects are taken into account by modifying the chiral symmetry breaking correlation, <q¯q>. Our results indicate a quenching of gA in a nuclear medium. The physical reasons for this fundamental quenching are noted to be the same for the effective mass of the nucleon bound in a nucleus being less than its free space value.