Color-octet quarkonia production
- Lauritsen Laboratory, California Institute of Technology, Pasadena, California 91125 (United States)
Gluon fragmentation represents the dominant source of high energy prompt quarkonia at hadron colliders. Fragmentation approximations break down, however, when a quarkonium{close_quote}s tranvserse momentum becomes comparable to its mass. In this paper we identify a large class of color-octet diagrams that mediate quarkonia production at all energies and reduce to the dominant set of gluon fragmentation graphs in the high {ital p}{sub {perpendicular}} limit. They contribute to quarkonia differential cross sections at the same order as color-singlet diagrams and bring theoretical predictions for {upsilon} and {psi} production at the Fermilab Tevatron into agreement with experimental measurements. Using recent CDF data we extract numerical values for bottomonia and charmonia color-octet matrix elements which are consistent with NRQCD scaling rules. We also find that quarkonia generated via the color-octet mechanism are strongly polarized at low as well as high energies. Spin alignment measurements can thus test the color-octet quarkonia production picture. {copyright} {ital 1995 The American Physical Society.}
- Research Organization:
- California Institute of Technology (CalTech), Pasadena, CA (United States)
- DOE Contract Number:
- FG03-92ER40701
- OSTI ID:
- 253516
- Journal Information:
- Physical Review, D, Vol. 53, Issue 1; Other Information: PBD: Jan 1996
- Country of Publication:
- United States
- Language:
- English
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