EVIDENCE FOR LONG-LIVED PROTON DECAY NOT FAR FROM THE BETA-STABILITY VALLEY PRODUCED BY THE O-16-197 REACTION AT 80 MEV(AU)

The reaction O-16 + Au-197 has been studied at a bombarding energy of 80 MeV. Long-lived proton decays with half-lives of about 5.8(-1.2)(+2 .2) h and 67.3(-19.5)(+46.4) h, proton energies of several MeV and pro duction cross-section in the nb region have been observed. The existen ce of long-lived high energy isomeric state(s) which decay by protons, directly or by delayed protons, is evident from the data. The possibl e connection with the second minimum in the potential energy curve is discussed.