First in-beam observation of97Ag — The three-proton-hole spectrum in100Sn

Excited states in97Ag have been identified for the first time following the reactions46Ti(58Ni,α p 2n and64Zn(36Ar,p 2n. The population cross sections were 1.0(5) mb and 0.7(3) mb, respectively. Theγ-decay of the seniorityΝ=3 states below theIπ=(17/2−) and (21/2+) isomers was investigated. In a search for short lived isomers half lives oft1/2=5(2) ns and 2.5(5) ns were found in theN=50 isotones97Ag,Iπ=(17/2−) and/or (21/2+) and95Rh,Iπ=(21/2+). A new isomer was identified in97Pd,Iπ=17/2+ witht1/2=2.3(5) ns. The implication of the three-proton hole spectrum in100Sn for the empirical residual interaction and shell model predictions is discussed.