Weak radiative hyperon decays present us with a long-standing puzzle, namely the question of validity of a hadron-level theorem proven by Hara. We briefly discuss the conflict between expectations based on Hara's theorem and experiment as well as the way in which the quark model evades the theorem. Violation of Hara's theorem in the quark model is traced back to the issue of hadron compositeness and the nonequivalence of standard ways of imposing gauge-invariance condition at quark and hadron levels. This suggests that our understanding of nonlocal composite nature of hadrons may require some important change.
Nuclear Physics B Proceedings Supplements
- Pub Date:
- June 1996
- High Energy Physics - Phenomenology
- 10 pages, LaTeX, reformatted to dispense with the use of the espcrc2.sty file, to appear in the Proceedings of the conference "Production and Decay of Hyperons, Charm and Beauty Hadrons", Strasbourg, September 5-8, 1995