On the possible total collapse of the pairing in the isomeric [formula omitted] states of odd- A45Rh and 47Ag nuclei

Abstract

In certain three-particle states of odd- A with A ∼ 100−110 and specific [p 1p 2n 1] or [p 1n 1n 2] configurations, the combination of a strong blocking effect and a particularly strong p-n coupling may cause the total collapse of pairing (2 Δ → 0). The energy of such a level may sharply drop well below the pairing gap energy to occur near to the ground state. Evidence is presented that the well-known J π = 7 2 + anomalous isomeric states in odd- A 45Rh and 47Ag nuclei with E exc <100 keV may be the first examples of such low, pairing-free, three-particle levels with the configuration {[ p 1( g 9 2 ) n 1( g 7 2 )] 1 + n 2(r00 5/2) .