Magnetic moments of N17 and B17

H. Ueno, K. Asahi, H. Izumi, K. Nagata, H. Ogawa, A. Yoshimi, H. Sato, M. Adachi, Y. Hori, K. Mochinaga, H. Okuno, N. Aoi, M. Ishihara, A. Yoshida, G. Liu, T. Kubo, N. Fukunishi, T. Shimoda, H. Miyatake, M. Sasaki, T. Shirakura, N. Takahashi, S. Mitsuoka, and W.-D. Schmidt-Ott
Phys. Rev. C 53, 2142 – Published 1 May 1996
PDFExport Citation

Abstract

The magnetic moments of N17 and B17 were measured by using spin-polarized radioactive nuclear beams which were obtained from the projectile fragmentation reaction. The observed magnetic moment of N17, ‖μ(17N)‖=(0.352±0.002)μN, where μN is the nuclear magneton, falls outside the Schmidt lines. By virtue of a simplifying feature of nuclear structure inherent in a p1/2 valence nucleus, the deviation from the Schmidt value is attributed on firm ground to admixing of the configurations in which two neutrons in the sd shell are coupled to Jπ=2+. This interpretation is confirmed in standard shell-model calculations. The calculations reproduce fairly well the experimentally inferred amount of 2+ admixture, as well as the experimental magnetic moment itself. The magnetic moment for B17 was determined as ‖μ(17B)‖=(2.545±0.020)μN. The result is substantially smaller than the πp1/2 single-particle value, and the shell-model calculations indicate that the quenching of μ largely stems from Jπ=2+ configurations of the sd neutrons. The observed amount of quenching, however, is larger than the shell-model predictions, suggesting an enhanced contribution of the 2+ neutron configurations. This result is explained if the pairing energy for neutrons in the sd shell of a neutron-rich nucleus is assumed to diminish by about 30%. We also find that the use of the reduced pairing energy improves agreements in the magnetic moment and low-lying energy levels of N17 as well. © 1996 The American Physical Society.

  • Received 28 November 1995

DOI:https://doi.org/10.1103/PhysRevC.53.2142

©1996 American Physical Society

Authors & Affiliations

H. Ueno, K. Asahi, H. Izumi, K. Nagata, H. Ogawa, A. Yoshimi, H. Sato, M. Adachi, Y. Hori, and K. Mochinaga

  • Department of Applied Physics, Tokyo Institute of Technology, Oh-okayama 2-12-1, Meguro-ku, Tokyo 152, Japan

H. Okuno, N. Aoi, and M. Ishihara

  • Department of Physics, University of Tokyo, Hongo 7-3-1, Bunkyo-ku, Tokyo 113, Japan

A. Yoshida, G. Liu, T. Kubo, and N. Fukunishi

  • Institute of Physical and Chemical Research (RIKEN), Hirosawa 2-1, Wako-shi, Saitama 351-01, Japan

T. Shimoda, H. Miyatake, M. Sasaki, T. Shirakura, and N. Takahashi

  • Department of Physics, Osaka University, Machikaneyama 1-16, Toyonaka, Osaka 560, Japan

S. Mitsuoka

  • Department of Physics, Kyushu University, Hakozaki 6-10-1, Higashi-ku, Fukuoka 812, Japan

W.-D. Schmidt-Ott

  • Zweites Physikalisches Institut, Der Universität Göttingen, Bunsenstrasse 7-9, D-3400 Göttingen, Germany

References (Subscription Required)

Click to Expand
Issue

Vol. 53, Iss. 5 — May 1996

Reuse & Permissions
Access Options
Author publication services for translation and copyediting assistance advertisement

Authorization Required


×
×

Images

×

Sign up to receive regular email alerts from Physical Review C

Log In

Cancel
×

Search


Article Lookup

Paste a citation or DOI

Enter a citation
×