Effect of nuclear deformation on the observation of a low-energy super-Gamow-Teller state

Indications of octupole correlation in 84Sr

“…Thus, in 84 Sr, the E1 character is confirmed for the interconnecting γ-ray transitions of energies 680.1, 996.9, and 1001.4keV between Band 3 and the Yrast band. The values of the B(E1)/B(E2) ratios (0.014-0.081×10 −06 fm −2 ) are also comparable with even-even 118−124 Ba and 118−120 Xe nuclei [70] and the order of B(E1) values i.e, 0.13-3.43 × 10 −05 W.u is observed in the order of B(E1) values reported for octupole correlation in the mass A = 80 region [71]. The comparison of the B(E1)/B(E2) ratio, frequency ratio ω − /ω + , and energy displacement ΔE values are presented in 84 Sr with the 72 Se [12], 150 Sm [17], 152 Gd [17], 220 Ra [6], and 224 Th [18] nuclei already having the octupole correlation.…”

“…The B(E1)/B(E2) ratio values of 84 Sr show a similar trend as observed for 72 Se, where an octupole correlation was reported between negative parity and positive parity states. Further, the experimental B(E1)/B(E2) ratio values of Band 3 in 84 Sr are of the order as reported in even-even 118−124 Ba and 118−120 Xe nuclei [70]. The experimental B(E1) values in 84 Sr are greater than 10 −05 W.u.…”

“…The occurrence of quadrupole deformation, namely β and γ, having K π = 0 + and K π = 2 + was already seen in the mass A ≈ 80 region. The 70,72 Ge [19,20], 74 Se [21], 76,78,82 Kr [22][23][24] and 80,82 Sr [25,26] nuclei were reported to have K π = 2 + band. The Yrast band of Strontium (Sr) even-even isotopes having A 88 manifests a shape transition from deformed ( 80,82 Sr [25,26]) to spherical( 86,88 Sr [27,28]) at N = 44-46 and therefore, the 84 Sr is expected to be a transitional nucleus.…”