Eur. Phys. J. A 13, 81-85 (2002)

Quenching of neutron effective charge in neutron-rich nuclei and the ground-state spin-parity of

H. Ogawa¹, K. Asahi^{1, 2}, H. Ueno², K. Sakai¹, H. Miyoshi¹, D. Kameda¹, T. Suzuki¹, H. Izumi¹, N. Imai³, Y.X. Watanabe², K. Yoneda², N. Fukuda³, H. Watanabe², A. Yoshimi², W. Sato², N. Aoi³, M. Nagakura¹, T. Suga¹, K Yogo¹, A. Goto¹, T. Honda¹, Y. Kobayashi², W.-D. Schmidt-Ott⁴, G. Neyens⁵, S. Teughels⁵, A. Yoshida², T. Kubo² and M. Ishihara<sup>6

1</sup>  Department of Physics, Tokyo Institute of Technology, 2-12-1 Oh-okayama, Meguro, Tokyo 152-8551, Japan
²  RIKEN, 2-1 Hirosawa, Wako-shi, Saitama 351-0198, Japan
³  Department of Physics, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
⁴  Zweites Physikalisches Institut, Universität Göttingen, Bunsenstrasse 7-9, D-37073 Göttingen, Germany
⁵  Instituut voor Kern- en Stralingsfysica, University of Leuven, Celestijnenlaan 200 D, B-3001 Leuven, Belgium
⁶  RIKEN-BNL Research Center, Brookhaven National Laboratory, Upton, NY 11973, USA

(Received: 1 May 2001 / Revised version: 28 June 2001)

Abstract
The electric quadrupole moment of ¹⁷B and the g-factor of ¹⁷C were measured by using the fragmentation-induced nuclear polarization technique combined with the -NMR method. The experimental quadrupole moment of ¹⁷B is found strikingly close to that of the neutron closed-shell isotope ¹³B, indicating a strong quenching of the neutron E2 core-polarization charge. From the result obtained for the ¹⁷C g-factor, we can conclude that the ground-state spin-parity of is 3/2⁺.

PACS
21.10.Ky - Electromagnetic moments.
24.70.+s - Polarization phenomena in reactions.
25.70.Mn - Projectile and target fragmentation.

© Società Italiana di Fisica, Springer-Verlag 2002