Comparison of the color-evaporation model and the nonrelativistic QCD factorization approach in charmonium production

Journal Article · Fri Jul 01 04:00:00 EDT 2005 · Physical Review. D, Particles Fields

DOI:https://doi.org/10.1103/PhysRevD.72.014004· OSTI ID:20711046

Bodwin, Geoffrey T ^[1]; Braaten, Eric ^[2]; Lee, Jungil ^[3]

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1. High Energy Physics Division, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, Illinois 60439 (United States)
2. Physics Department, Ohio State University, Columbus, Ohio 43210 (United States)
3. Department of Physics, Korea University, Seoul 136-701 (Korea, Republic of)

We compare the color-evaporation model (CEM) and nonrelativistic QCD (NRQCD) factorization predictions for inclusive quarkonium production. Using the NRQCD factorization formulas for quarkonium production and for perturbative QQ production, we deduce relationships that are implied by the CEM between the nonperturbative NRQCD matrix elements that appear in the factorization formula for quarkonium production. These relationships are at odds with the phenomenological values of the matrix elements that have been extracted from the Tevatron data for charmonium production at large transverse momentum. A direct comparison of the CEM and NRQCD factorization predictions with the CDF charmonium production data reveals that the CEM fits to the data are generally unsatisfactory, while the NRQCD factorization fits are generally compatible with the data. The inclusion of k{sub T} smearing improves the CEM fits substantially, but significant incompatibilities remain. The NRQCD factorization fits to the {chi}{sub c} data indicate that multiple gluon radiation is an essential ingredient in obtaining the correct shape of the cross section as a function of p{sub T}.

• OSTI ID: 20711046
• Journal Information: Physical Review. D, Particles Fields, Journal Name: Physical Review. D, Particles Fields Journal Issue: 1 Vol. 72; ISSN PRVDAQ; ISSN 0556-2821
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
CHARMONIUM
COLOR MODEL
COMPARATIVE EVALUATIONS
FACTORIZATION
FERMILAB COLLIDER DETECTOR
FERMILAB TEVATRON
GLUONS
INCLUSIVE INTERACTIONS
MATRIX ELEMENTS
PERTURBATION THEORY
PROTON-PROTON INTERACTIONS
QUANTUM CHROMODYNAMICS
TRANSVERSE MOMENTUM