Strong U{sub A}(1) breaking in radiative {eta} decays and baryon systems
- Institute for Nuclear Study, University of Tokyo, Tanashi, Tokyo 188 (Japan)
- Department of Physics, Tokyo Institute of Technology, Meguro, Tokyo 152 (Japan)
We study the {eta}{r_arrow}{gamma}{gamma}, {eta}{r_arrow}{gamma}{mu}{sup {minus}}{mu}{sup +}, and {eta}{r_arrow}{pi}{sup 0}{gamma}{gamma} decays using an extended three-flavor Nambu{endash}Jona-Lasinio model that includes the `t Hooft instanton induced interaction. We find that the {eta}-meson mass, the {eta}{r_arrow}{gamma}{gamma}, {eta}{r_arrow}{gamma}{mu}{sup {minus}}{mu}{sup +}, and {eta}{r_arrow}{pi}{sup 0}{gamma}{gamma} decay widths are in good agreement with the experimental values when the U{sub A}(1) breaking is strong and the flavor SU(3) singlet-octet mixing angle {theta} is about zero. The calculated {eta}{gamma}{gamma}{sup {asterisk}} transition form factor has a somewhat weaker dependence on the squared four-momentum of the virtual photon. The effects of the U{sub A}(1) anomaly on the scalar quark contents in the nucleon, the {Sigma}{sub {pi}N} and {Sigma}{sub KN} terms, and the baryon number one and two systems are also studied. {copyright} {ital 1997} {ital The American Physical Society}
- OSTI ID:
- 477073
- Journal Information:
- Physical Review, D, Journal Name: Physical Review, D Journal Issue: 7 Vol. 55; ISSN PRVDAQ; ISSN 0556-2821
- Country of Publication:
- United States
- Language:
- English
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