Coexistence of shapes and the role of the g_9/2orbit in Se isotopes

Deformed shell model results for two-neutrino positron double-βdecay ofSe74

“…DSM with modified Kuo effective interaction has been quite successfully used by us to describe many important features of nuclei in the A ∼ 60-80 region. In particular, shape coexistence in spectra, observed B(E2) values, and band crossings in 70,72,74 Se isotopes are well described by DSM [35]. We have also verified that 74 Ge spectroscopic properties are well described by DSM.…”

Coulomb shifts and shape changes in the mass 70 region

“…Shape changes in 70 Se are clear experimentally from the very irregular yrast line and lifetime measurements, which indicated a strong reduction in B(E2) transition strengths near J = 4 [25]. A recent Coulomb excitation measurement favors a prolate shape for the 2 + state consistent with β 2 = 0.25 [7] and is in agreement with a configuration mixing shell model calculation which predicts a ground state band with β 2 = 0.18 crossed by a more deformed band with β 2 = 0.33 near J = 6 [30]. For such a shape change, the deformed liquid drop model suggests a ∼ 75 keV decrease in CED, in good agreement with that observed in the present work.…”

Computer Simulation of Ultrasonic Images with Self-Similarity of Tissue Structures

“…As has been discussed in our earlier publication (Sahu et al 1987), the HF calculations in this region often give an oblate state as the energetically lowest intrinsic state, about 3 4 MeV lower than the lowest prolate state. The general systematics indicate that all nuclei in the region A Y 80 are prolate at least in the low-energy states.…”

“…Over the last few years, we have been studying nuclei in this region within our deformed configuration mixing (DCM) shell model based on Hartree-Fock states. We have been able to explain successfnlly a rich variety of phenomena in this region (Ahalpara et al 1985, Ahalpara and Pandya 1986, Sahu 1989, Sahu et al 1987 to 0.29 for "SI. These nuclei have also been studied theoretically by many groups.…”