| Biography | |
|---|---|
 Prof. Shuifa Shen Institute of Nuclear Energy Safety Technology, CAS, China |
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| Title: High-spin states and level structure in 80Rb and 84Rb | |
| Abstract: High-spin states of 80Rb are studied via the fusion-evaporation reactions 65Cu+19F, 66Zn+18O, and 68Zn+16O with the beam energies of 75 MeV, 76 MeV, and 80 MeV, respectively. Twenty-three states with twenty-eight γ transitions are added to the previously proposed level scheme, where the second negative-parity band is significantly pushed up to spins of 22− and 15− and two sidebands are built on the known first negative-parity band. Two successive band crossings with frequencies 0.51 MeV and 0.61 MeV in the α=0 branch as well as another one in the α=1 branch of the second negative-parity band are observed. Signature inversions occur in the positive-parity and first negative-parity bands at the spins of 11 and 16 , respectively. The signature splitting is seen obviously in the second negative-parity band, but the signature inversion is not observed. It is also found that the structure of the two negative-parity bands is similar to that of its isotone 82Y. Signature inversion in the positive parity yrast band with configuration πg9/2×νg9/2 in this nucleus is discussed using the projected shell model. High-spin states in 84Rb have been studied by using the 70Zn(18O,p3n)84Rb reaction at beam energy of 75 MeV. The γ-γ coincidence, excitation function, and ratios for directional correlation of oriented states were determined. A new level scheme was established in which the positive- and negative-parity bands have been extended up to 17+ and 17- with an excitation energy of about 7 MeV. The signature splitting and signature inversion of the positive-parity yrast band were observed. To understand the microscopic origin of the signature inversion in the yrast positive-parity bands of doubly odd Rb nuclei, as an example, we performed calculations using the projected shell model to describe the energy spectra in 84Rb. It can be seen that the main features are reproduced in the calculations. This analysis shows that the signature splitting, especially its inversion, can be reproduced by varying only the γ deformation with increasing spin. To research the deformation of 84Rb carefully, we calculate the total Routhian surfaces of positive-parity yrast states by the cranking shell model formalism. In addition, the results of theoretical calculations about the negative-parity yrast band in 84Rb with configuration π(p3/2, f5/2)×υ9/2 are compared with experimental data, and a band diagram calculated for this band is also shown to extract physics from the numerical results. | |
| Biography: Prof. Shuifa Shen: 2002–2005, Doctor of Particle Physics and Nuclear Physics, Shanghai Institute of Applied Physics, CAS. 2006–2008, Postdoctoral Researcher, School of Physics, Peking University. 2010–2012, Postdoctoral Researcher, School of Physics, Suranaree University of Technology, Thailand. 2018-2019, Senior Research Fellow, Department of Physics, University of Surrey, the United Kingdom. 2013 – present, Institute of Nuclear Energy Safety Technology, CAS. He is the leader of more than 30 research projects including National Natural Science Foundation. More than 70 papers were published in peer-reviewed journals and international conferences. Synthesis and Identification of new nuclide 235Am won one of the top ten news in science and technology in our China in 1996. He was awarded the special allowance of the State Council in 2007, chosen as the key teacher of colleges and universities in Jiangxi province in 2007, selected as new century Talents Project in Jiangxi Province in 2009, and selected as the chair professor of Minjiang Scholars Program in Fujian Province in 2019. | |
