Higher Fock states and power counting in exclusive P-wave quarkonium decays
| Autor: | Peter Kroll, Gerhard A. Schuler, Jan Bolz |
|---|---|
| Rok vydání: | 1997 |
| Předmět: |
Physics
Particle physics Physics and Astronomy (miscellaneous) High Energy Physics::Phenomenology Momentum transfer Hadron Order (ring theory) FOS: Physical sciences Quarkonium Fock space High Energy Physics - Phenomenology Pion Fock state High Energy Physics - Phenomenology (hep-ph) High Energy Physics::Experiment Wave function Nuclear Experiment Engineering (miscellaneous) Particle Physics - Phenomenology |
| DOI: | 10.48550/arxiv.hep-ph/9704378 |
| Popis: | Exclusive processes at large momentum transfer Q factor into perturbatively calculable short-distance parts and long-distance hadronic wave functions. Usually, only contributions from the leading Fock states have to be included to leading order in 1/Q. We show that for exclusive decays of P-wave quarkonia the contribution from the next-higher Fock state |Q Qbar g> contributes at the same order in 1/Q. We investigate how the constituent gluon attaches to the hard process in order to form colour-singlet final-state hadrons and argue that a single additional long-distance factor is sufficient to parametrize the size of its contribution. Incorporating transverse degrees of freedom and Sudakov factors, our results are perturbatively stable in the sense that soft phase-space contributions are largely suppressed. Explicit calculations yield good agreement with data on chi_{c J} decays into pairs of pions, kaons, and etas. We also comment on J/psi decays into two pions. Latex, 25 pages, 5 figures |
| Databáze: | OpenAIRE |
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