1 l.D.3 1 zyxwvutsrqponmlkjihgfedcbaZYXWVUTSRQPONMLKJIHGFEDCBA NucIear Physics A147 (1970) 369-384; @ North-Holland Publishing Co., Amsterdam Not to be reproduced by photoprint or microfilm without written permission from the publisher PROPERTIES OF 63Cu NEGATIVE PARITY STATES IN THE SEMIMICROSCOPIC MODEL V. PAAR Institute “Rudjer BoSkoviC”, Zagreb and The Niels Bohr Institute, University of Copenhagen, Denmark Received 23 December 1969 (Revised 11 March 1970) Abstract: The semimicroscopic model assuming zyxwvutsrqponmlkjihgfedcbaZYXWVUTSRQPONMLKJIH a proton coupled to a quadrupole vibrator, with states up to three phonons included, is applied to 63Cu. Parametrization different from that by Bouten and Van Leuven is used. Blair’s spectroscopic factors are well reproduced, and the experimen- tally known properties of B(E2) values are obtained. The influence of particle-hole excitations in the internal phonon structure within this parametrization appears to be small. The configuration I(fs -‘ps)2) is a dominant proton excitation in the one-phonon state. 1. Introduction In the particle-vibration coupling model, the 63Cu nucleus has been treated pre- viously by Bouten and Van Leuven ‘) with states up to two phonons included. The phonon frequency was taken from 62Ni, and positions of the single-particle valence states p+ ft and pt were obtained by the least-square fit to the energies of the five lowest excited states in 63Cu. In this par ametrization, the spectroscopic factor of the first excited +- state was too small, 29 instead of 70, as determined in ref. “). On the other hand, by repeating the calculations of ref. ‘), we found that spectroscopic factors of some higher levels disagree with experiments. For example, the calculated 3 states at 2.0 MeV, 2.8 MeV and 3.3 MeV have spectroscopic factors 25, 12 and 28, respectively, while the experimental spectroscopic factors of the corresponding states are “) 23, 1 and 4, respectively. A large spectroscopic factor (76) of the first excited state was obtained in the “weak coupling theory” “). Quadrupole-quadrupole and dipole-dipole interactions have been taken into account. The single-particle states pt, pt, f5 and the single- particle state p+ coupled to the 2+ core state were included. The core matrix elements were taken as free parameters. In this way, only six states in 63Cu have been obtained. The highest predicted state (3)2 occurred in the region of three levels found experi- mentally. The inclusion of a core coupled to p+ and f+ single-particle states would change the B(E2) values and reduce the spectroscopic factors. Especially, as mentioned in 6), the critical & -+ $I transition could be strongly affected. The 63Cu nucleus has been treated in the quasiparticle description by Beres ‘). 369