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Title: Strong U{sub A}(1) breaking in radiative {eta} decays and baryon systems

Abstract

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}

Authors:
 [1]; ;  [2]
  1. Institute for Nuclear Study, University of Tokyo, Tanashi, Tokyo 188 (Japan)
  2. Department of Physics, Tokyo Institute of Technology, Meguro, Tokyo 152 (Japan)
Publication Date:
OSTI Identifier:
477073
Resource Type:
Journal Article
Journal Name:
Physical Review, D
Additional Journal Information:
Journal Volume: 55; Journal Issue: 7; Other Information: PBD: Apr 1997
Country of Publication:
United States
Language:
English
Subject:
66 PHYSICS; U-1 GROUPS; SYMMETRY BREAKING; ETA MESONS; RADIATIVE DECAY; FLAVOR MODEL; INSTANTONS; PHOTONS; SU-3 GROUPS; BARYON NUMBER; MIXING RATIO; FORM FACTORS

Citation Formats

Takizawa, M, Nemoto, Y, and Oka, M. Strong U{sub A}(1) breaking in radiative {eta} decays and baryon systems. United States: N. p., 1997. Web. doi:10.1103/PhysRevD.55.4083.
Takizawa, M, Nemoto, Y, & Oka, M. Strong U{sub A}(1) breaking in radiative {eta} decays and baryon systems. United States. https://doi.org/10.1103/PhysRevD.55.4083
Takizawa, M, Nemoto, Y, and Oka, M. Tue . "Strong U{sub A}(1) breaking in radiative {eta} decays and baryon systems". United States. https://doi.org/10.1103/PhysRevD.55.4083.
@article{osti_477073,
title = {Strong U{sub A}(1) breaking in radiative {eta} decays and baryon systems},
author = {Takizawa, M and Nemoto, Y and Oka, M},
abstractNote = {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}},
doi = {10.1103/PhysRevD.55.4083},
url = {https://www.osti.gov/biblio/477073}, journal = {Physical Review, D},
number = 7,
volume = 55,
place = {United States},
year = {1997},
month = {4}
}