The geometric similarity of wave functions assuming isoscalar spin-aligned and isovector pairing correlations challenges our understanding of the isospin nature for nucleon pairs in low-lying nuclear states. Instead of energy levels and electromagnetic properties, integrated Gamow-Teller decay rates are found to be sensitive and parameter-free quantities to discriminate between the two scenarios in ${}^{96}\mathrm{Cd}$. Analytical formulas of the decay rates for $T=0$ yrast states of ${}^{96}\mathrm{Cd}$ are derived from a single-$j$ ($g_{9/2}$) shell, the validity of which model space is supported by examining details of Gamow-Teller transition rates with shell-model calculations using three sets of effective interactions in the $f_{5}p{g}_9$ shell. The experimental $logft$ value of the $0_1^{+}$ ground state does not conform with spin-aligned pair condensation and is more appropriate to interpret in terms of the conventional isovector pairing correlation; on the other hand, for the isomeric ${16}_1^{+}$ state, the experimental datum is well consistent with the isoscalar spin-aligned pair condensation.

Close

PrevNext

View figure in article

• Nuclear forces
• Nuclear structure & decays
• 90 ≤ A ≤ 149