SDPF-U

Is the 7/2₁^– Isomer State of ⁴³S Spherical?

R. Chevrier et al.

doi: 10.1103/PhysRevLett.108.162501

We report on the spectroscopic quadrupole moment measurement of the 7/2₁^– isomeric state in ⁴³₁₆S₂₇ [E^*=320.5(5)  keV, T_1/2=415(3)  ns], using the time dependent perturbed angular distribution technique at the RIKEN RIBF facility. Our value, ∣Q_s∣=23(3)  efm², is larger than that expected for a single-particle state. Shell model calculations using the modern SDPF-U interaction for this mass region reproduce remarkably well the measured ∣Q_s∣, and show that non-negligible correlations drive the isomeric state away from a purely spherical shape.