Eur. Phys. J. A (2008) 35: 57-68
https://doi.org/10.1140/epja/i2007-10519-x

Regular Article - Theoretical Physics

Investigation on phase and shape transitions in the hot rotating nucleus ¹⁵⁴Dy

Department of Physics, Manonmaniam Sundaranar University, 627 012, Abishekapatti, Tirunelveli, Tamil Nadu, India

^* e-mail: trrajasekaran@gmail.com

Received: 25 June 2007
Accepted: 13 January 2008
Published online: 27 February 2008

Abstract

A statistical theory for hot rotating nuclei incorporating deformation, collective and non-collective rotational degrees of freedom, shell effects and pairing correlations is used to investigate the occurrence of phase and shape transitions in the hot rotating deformed nucleus ¹⁵⁴Dy . The interplay of various degrees of freedom and their influence on the behavior of nuclei formed as fused compounds in heavy-ion reactions are studied. A phase transition from the superfluid to normal state in the nucleus with increasing temperature and angular momentum is observed. The effect of pairing on the level density parameter and nucleon separation energy has been analyzed and is found to be substantial. The neutron and proton separation energies extracted as a function of the angular momentum and temperature is found to decrease sharply for particular angular momentum states of the nucleus due to shape transitions from prolate collective to oblate non-collective at higher temperatures.