Testing quarkonium production with photoproduced J/{psi}+{gamma}
- Department of Physics and Astronomy, The Johns Hopkins University, 3400 North Charles Street, Baltimore, Maryland 21218 (United States)
I compute the leading color-octet contributions to the process {gamma}+p{r_arrow}J/{psi}+{gamma}(+X) within the nonrelativistic QCD (NRQCD) factorization formalism. In the color-singlet model, J/{psi}+{gamma} can only be produced when the photon interacts through its structure function, while the color-octet mechanism allows for production of J/{psi}+{gamma} via direct photon-gluon fusion. Resolved photon processes can be distinguished easily from direct photon processes by examining the fraction of the incident photon energy carried away by the J/{psi} in the event. Therefore, this process provides a conclusive test of the color-octet mechanism. J/{psi}+{gamma} production is particularly sensitive to the NRQCD matrix element which figures prominently in the fragmentation production of J/{psi} at large p{sub {perpendicular}} in hadron colliders. I also examine the predictions of the color evaporation model (CEM) of quarkonium production and find that this process can easily discriminate between the NRQCD factorization formalism and the CEM. {copyright} {ital 1997} {ital The American Physical Society}
- OSTI ID:
- 477091
- Journal Information:
- Physical Review, D, Vol. 55, Issue 7; Other Information: PBD: Apr 1997
- Country of Publication:
- United States
- Language:
- English
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