Eur. Phys. J. A (2006) 27: 325-340
https://doi.org/10.1140/epja/i2006-10006-0

Nuclear Structure and Reactions

Lifetimes and side-feeding population of the yrast band levels in ¹³¹La

¹ Nuclear Physics Division, Warsaw University, Hoża 69, 00-681, Warsaw, Poland
² Cyclotron Laboratory, A.F. Ioffe Physical Technical Institute, 194021, St.-Petersburg, Russia
³ The A. Sołtan Institute for Nuclear Studies, 05-400, Świerk, Poland
⁴ Heavy Ion Laboratory, Warsaw University, Warsaw, Poland

^* e-mail: egrodner@npdoxp.fuw.edu.pl

Received: 6 February 2006
Accepted: 9 March 2006
Published online: 12 April 2006

Abstract

Lifetimes of yrast levels with spins I ^π = 23/2^--43/2^- in ¹³¹La populated in the ¹²²Sn(¹⁴N, 5n) reaction at a beam energy of 70MeV are measured by the Doppler Shift Attenuation method. A model of side-feeding population is presented. The model parameters are determined in an experiment based on the lineshape of γ-transitions from two highest spin levels and from the intensity distribution along the yrast band. The properties of the h _11/2 band in ¹³¹La are compared with the theoretical predictions obtained in the framework of the Core-Quasi-Particle Coupling and the self-consistent Total Routhian Surface models.