Heavy Quarkonium Production at HERA
Abstract
In this article, recent results an electro- and photoproduction of heavy vector mesons at HERA are reviewed. Various models for the inelastic and elastic production mechanisms are discussed and confronted with the measurements. Elastic production allows comparison of two distinct theoretical concepts, i.e. the Regge ansatz and models using perturbative QCD (pQCD), where the colorless exchange is modeled by multiple gluon exchange. While production of light vector mesons is well described in the Regge picture, the heavy vector meson data show clear deviations from the universal "soft" Pomeron prediction. Perturbative QCD, however, is able to reproduce the trend of the data, as well as a more general Regge fit using an additional "hard" Pomeron.
- Publication:
-
New Trends in Hera Physics 1999
- Pub Date:
- 2000
- Bibcode:
- 2000LNP...546..303K
- Keywords:
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- PACS: 14.20.Dh;
- 25.30.-c;
- 14.70.-e;
- 13.88.+e;
- 13.65.+i