Structure of positive-parity yrast band in 80 Br

✍ Scribed by I. Ray; P. Banerjee; S. Bhattacharya; M. Saha-Sarkar; S. Muralithar; R.P. Singh; R.K. Bhowmik

• Publisher: Elsevier Science
• Year: 2000
• Tongue: English
• Weight: 251 KB
• Volume: 678
• Category: Article
• ISSN: 0375-9474
• DOI: 10.1016/s0375-9474(00)00335-3

✦ Synopsis

The states of the positive-parity yrast band in 80 Br have been investigated using the 76 Ge( 7 Li, 3nγ ) reaction at a beam energy of 32 MeV. The band has been extended up to 4450 keV with a spin of (14 + ). Unambiguous spin assignments are made for states up to 2944.0 keV and γ -ray multipole mixing ratios are determined for several J = 1 transitions. Lifetimes studies for the 10 + , 11 + and 12 + states provide an estimate of the quadrupole deformation in this band. Cranking model analysis of the experimental data reveals a signature inversion at a spin of 12 h and a probable neutron alignment at hω ≈ 0.7 MeV. The results are discussed within the framework of the systematics of similar bands in the lighter Br isotopes and the cranked-shell model. In addition, a new positiveparity and two negative-parity sequences have been identified.