SEARCH FOR TWO-PHONON OCTUPOLE VIBRATIONAL BANDS IN ^{88, 89, 92, 93, 94, 96}Sr AND ^{95, 96, 97, 98}Zr.

HWANG, J. K.; HAMILTON, J. H.; RAMAYYA, A. V.; BREWER, N. T.; WANG, E. H.; LUO, Y. X.; ZHU, S. J.

Several new gamma transitions were identified in 94Sr, 93Sr, 92Sr, 96Zr and 97Zr from the spontaneous fission of 252Cf. Excited states in 88, 89, 92, 94, 96Sr and 95, 96, 97, 98Zr were reanalyzed and reorganized to propose the new two-phonon octupole vibrational states and bands. The spin and parity of 6 are assigned to a 4034.5 keV state in 94Sr and 3576.4 keV state in 98Zr. These states are proposed as the two-phonon octupole vibrational states along with the 6 states at 3483.4 keV in 96Zr, at 3786.0 keV in 92Sr and 3604.2 keV in 96Sr. The positive parity bands in 88, 94, 96Sr and 96, 98Zr are the first two-phonon octupole vibrational bands based on a 6 state assigned in spherical nuclei. It is thought that in 94, 96Sr and 96, 98Zr a 3− octupole vibrational phonon is weakly coupled to an one-phonon octupole vibrational band to make the two-phonon octupole vibrational band. Also, the high spin states of odd-A 95Zr and 97Zr are interpreted to be generated by the neutron 2d5/2 hole and neutron 1g7/2 particle, respectively, weakly coupled to one- and two-phonon octupole vibrational bands of 96Zr. The high spin states of odd-A 87Sr are interpreted to be caused by the neutron 1g9/2 hole weakly coupled to 3− and 5− states of 88Sr. New one- and two-POV bands in 95, 97Zr and 87, 89Sr are proposed, for the first time, in the present work.

PHONONS; VIBRATION (Mechanics); NUCLEAR fission; NUCLEAR spin; ENERGY bands; STRONTIUM isotopes; EXCITED state chemistry; GAMMA rays

International Journal of Modern Physics E: Nuclear Physics, 2012, Vol 21, Issue 9, p1250080-1

0218-3013

Academic Journal

10.1142/S0218301312500802