High Spin Physics 2001, Warsaw, February 6-10, 2001



Abstract No: 042
Submitted on: 24 Jan 2001, 13:08 GMT
Title: Determination of quadrupole deformation parameters of the 165Ho nucleus in excited states
Author(s): M. Zielinska,1 J. Iwanicki,1T. Czosnyka,1J. Choinski,1P. Napiorkowski,1M. Loewe,2M. Würkner,2 and J. Srebrny3
Affiliation(s): 1Heavy Ion Laboratory of Warsaw University, 2Sektion Physik, Universität München, 3Institute of Experimental Physics, Warsaw University




The ground state level of the 165Ho nucleus may be understood as built by a single proton occupying the Nilsson orbital [523] around a 164Dy core which gives the spin of 7/2 and negative parity.

The nucleus may undergo a $\gamma$ vibration and the spin of a phonon may be subtracted or added to the ground state spin and these two possibilities give two other rotational $\gamma$ bands starting from the states 3/2- and 11/2-, respectively.

A remarkable change of quadrupole moment in one of the $\gamma$-vibrational bands was found.

Coulomb Excitation experiments, using O, Ne and Ar beams, were performed at the Heavy Ion Laboratory of Warsaw University using the CUDAC and Osiris set-ups.

A model-independent analysis using the GOSIA code yielded a set of reduced matrix elements values coupling the low-lying collective excited states. A quadrupole sum rules approach was used to determine the deformation of the states.

\fbox{ Preferred presentation of the contribution: in the poster session. }