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Title: Off-shell and non-static contributions to heavy-quarkonium production

Abstract

We have shown that if one relaxes the constraint that the quarks in a heavy quarkonium are at rest and on-shell, new contributions to the discontinuity of the production amplitude appear. These can be seen as a s-cut in the amplitude and are on the same footage as the classical cut of the Colour-Singlet Model (CSM), where the heavy quarks forming the quarkonium are put on-shell by hypothesis. We treat this cut in a gauge-invariant manner by introducing necessary new 4-point vertices, suggestive of the colour-octet mechanism. We have further shown that this cut contributes at least as much as the LO CSM at large PT. However, the 4-point vertices cannot be totally constrained and an ambiguity remains to what concerns their actual contribution. Theoretical insights from meson photoproduction are discussed in that context.

Authors:
 [1];  [2]
  1. Centre de Physique Theorique, Ecole polytechnique, CNRS, 91128 Palaiseau (France)
  2. (Belgium)
Publication Date:
OSTI Identifier:
21056845
Resource Type:
Journal Article
Resource Relation:
Journal Name: AIP Conference Proceedings; Journal Volume: 892; Journal Issue: 1; Conference: QCHS7: 7. conference on quark confinement and the hadron spectrum, Ponta Delgada, Acores (Portugal), 2-7 Sep 2006; Other Information: DOI: 10.1063/1.2714407; (c) 2007 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; AMPLITUDES; B QUARKS; C QUARKS; COLOR MODEL; GAUGE INVARIANCE; MESONS; PHOTOPRODUCTION; QUARKONIUM; RESONANCE PARTICLES; T QUARKS

Citation Formats

Lansberg, J. P., and Physique theorique fondamentale, Departement de Physique, Universite de Liege, allee du 6 Aout 17, bat. B5, B-4000 Liege 1. Off-shell and non-static contributions to heavy-quarkonium production. United States: N. p., 2007. Web. doi:10.1063/1.2714407.
Lansberg, J. P., & Physique theorique fondamentale, Departement de Physique, Universite de Liege, allee du 6 Aout 17, bat. B5, B-4000 Liege 1. Off-shell and non-static contributions to heavy-quarkonium production. United States. doi:10.1063/1.2714407.
Lansberg, J. P., and Physique theorique fondamentale, Departement de Physique, Universite de Liege, allee du 6 Aout 17, bat. B5, B-4000 Liege 1. Tue . "Off-shell and non-static contributions to heavy-quarkonium production". United States. doi:10.1063/1.2714407.
@article{osti_21056845,
title = {Off-shell and non-static contributions to heavy-quarkonium production},
author = {Lansberg, J. P. and Physique theorique fondamentale, Departement de Physique, Universite de Liege, allee du 6 Aout 17, bat. B5, B-4000 Liege 1},
abstractNote = {We have shown that if one relaxes the constraint that the quarks in a heavy quarkonium are at rest and on-shell, new contributions to the discontinuity of the production amplitude appear. These can be seen as a s-cut in the amplitude and are on the same footage as the classical cut of the Colour-Singlet Model (CSM), where the heavy quarks forming the quarkonium are put on-shell by hypothesis. We treat this cut in a gauge-invariant manner by introducing necessary new 4-point vertices, suggestive of the colour-octet mechanism. We have further shown that this cut contributes at least as much as the LO CSM at large PT. However, the 4-point vertices cannot be totally constrained and an ambiguity remains to what concerns their actual contribution. Theoretical insights from meson photoproduction are discussed in that context.},
doi = {10.1063/1.2714407},
journal = {AIP Conference Proceedings},
number = 1,
volume = 892,
place = {United States},
year = {Tue Feb 27 00:00:00 EST 2007},
month = {Tue Feb 27 00:00:00 EST 2007}
}