{gamma}{pi}{r_arrow}{pi}{pi} in a confined quark model
- Department of Physics, Virginia Polytechnic Institute and State University, Blacksburg, Virginia 24061 (United States)
A confined quark model study in a couple of {ital chirally anomalous} processes is presented in comparison with effective meson Lagrangian approaches of various kinds. The processes considered are {pi}{sup 0}{r_arrow}{gamma}{gamma} and {gamma}{r_arrow}{pi}{sup +}{pi}{sup {minus}}{pi}{sup 0} (or the equivalent {pi}{gamma}{r_arrow}{pi}{pi}) for which there is a well-known low energy theorem relating the latter amplitude with the former one by a very simple algebraic relation in the zero energy (or chiral, or soft pion) limit. Our quark model naturally generates the so-called contact term in the amplitude for the second process, but with the opposite sign to what effective chiral meson models indicate. A reinterpretation of our vector pole contribution restores the consistency, however. While the first reaction is observed to serve in {ital calibrating} various models, it is found difficult, based upon the quality of the existing data in the second reaction, to single out the {ital best} {ital model,} which appears indispensable for testing the validity of the above low energy theorem. Thus the proposed experiments and their analyses should aim at attaining an optimal accuracy. {copyright} {ital 1996 The American Physical Society.}
- OSTI ID:
- 278578
- Journal Information:
- Physical Review, D, Journal Name: Physical Review, D Journal Issue: 3 Vol. 53; ISSN PRVDAQ; ISSN 0556-2821
- Country of Publication:
- United States
- Language:
- English
Similar Records
Resonant and nonresonant D{sup +}{r_arrow}K{sup {minus}}{pi}{sup +}l{sup +}{nu}{sub l} semileptonic decays
Search for the scalar a{sub 0} and f{sub 0} mesons in the reactions e{sup +}e{sup {minus}}{r_arrow}{gamma}{pi}{sup 0}{pi}{sup 0}({eta})