Up-Down Quark Mass Difference Effect in Nuclear Many-Body Systems

S. Nakamura; K. Muto; M. Oka; S. Takeuchi; T. Oda

doi:10.1103/PhysRevLett.76.881

Up-Down Quark Mass Difference Effect in Nuclear Many-Body Systems

S. Nakamura, K. Muto, M. Oka, S. Takeuchi, and T. Oda

Phys. Rev. Lett. 76, 881 – Published 5 February 1996

Abstract

A charge-symmetry-breaking nucleon-nucleon force due to the up-down quark mass difference is evaluated in the quark cluster model. It is applied to the shell-model calculation for the isovector mass shifts of isospin multiplets in $1 s 0 d$ -shell nuclei. We find that the contribution of the quark mass difference effect explains the systematic behavior of experiment. This contribution is large and may explain the Okamoto-Nolen-Schiffer anomaly, alternatively to the meson-mixing contribution, which is recently predicted to be reduced by the large off-shell correction.

Received 20 January 1995

DOI:https://doi.org/10.1103/PhysRevLett.76.881

Authors & Affiliations

S. Nakamura¹, K. Muto², M. Oka², S. Takeuchi³, and T. Oda²

¹Institute for Nuclear Study, University of Tokyo, Tokyo 188, Japan
²Department of Physics, Tokyo Institute of Technology, Tokyo 152, Japan
³Department of Public Health and Environmental Science, Tokyo Medical and Dental University, Tokyo 113, Japan