Eur. Phys. J. A (2006) 27: 137-141
https://doi.org/10.1140/epja/i2005-10196-9

Nuclear Structure and Reactions

Shape-driving effect of the proton 1/2[541] band in ¹⁷¹Ta

¹ China Institute of Atomic Energy, 102314, Beijing, PRC
² College of Physics, Jilin University, 130023, Changchun, PRC
³ Institute of Modern Physics, 730000, Lanzhou, PRC
⁴ Cyclotron Lab., A.F. Ioffe Physical Technical Institute, St. Petersburg, Russia
⁵ Institute of Low Energy Nuclear Physics, Beijing Normal University, 100875, Beijing, PRC
⁶ School of Physics, Peking University, 100871, Beijing, PRC
⁷ School of Science, Shenzhen University, 518060, Shenzhen, PRC

^* e-mail: zhulh@iris.ciae.ac.cn

Received: 27 January 2005
Accepted: 10 January 2006
Published online: 14 March 2006

Abstract

High-spin states in ¹⁷¹Ta were populated through the heavy-ion fusion-evaporation reaction ¹⁵⁷Gd (¹⁹F, 5n)¹⁷¹Ta at 105MeV beam energy. Lifetimes of the levels of the πh _9/21/2[541] band have been measured by using the Doppler shift attenuation method. The transition quadrupole moments ( Q _t) and the quadrupole deformation (β₂) have been extracted. Both β₂ and Q _t values decrease slightly with increasing rotational frequency. The average β₂ value of 0.26 is 18% larger than that of the πh _11/2 9/2[514] band. Total Routhian Surface calculations have been performed with the non-axial deformed Woods-Saxon potential and the predicted values of the quadrupole deformation β₂ are in good agreement with that deduced from our lifetime measurement. The shape-driving effect is discussed.