Resummation of large endpoint corrections to color-octet J/{psi} photoproduction

Journal Article · Fri Dec 01 04:00:00 EST 2006 · Physical Review. D, Particles Fields

DOI:https://doi.org/10.1103/PHYSREVD.74.114004· OSTI ID:20868084

Fleming, Sean ^[1]; Leibovich, Adam K ^[2]; Mehen, Thomas ^[3]

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1. Physics Department, University of Arizona, Tucson, Arizona 85721 (United States)
2. Department of Physics and Astronomy, University of Pittsburgh, Pittsburgh, Pennsylvania 15260 (United States)
3. Department of Physics, Duke University, Durham, North Carolina 27708 (United States)

An unresolved problem in J/{psi} phenomenology is a systematic understanding of the differential photoproduction cross section, d{sigma}/dz[{gamma}+p{yields}J/{psi}+X], where z=E{sub {psi}}/E{sub {gamma}} in the proton rest frame. In the nonrelativistic QCD (NRQCD) factorization formalism, fixed-order perturbative calculations of color-octet mechanisms suffer from large perturbative and nonperturbative corrections that grow rapidly in the endpoint region, z{yields}1. In this paper, NRQCD and soft collinear effective theory are combined to resum these large corrections to the color-octet photoproduction cross section. We derive a factorization theorem for the endpoint differential cross section involving the parton distribution function and the color-octet J/{psi} shape functions. A one-loop matching calculation explicitly confirms our factorization theorem at next-to-leading order. Large perturbative corrections are resummed using the renormalization group. The calculation of the color-octet contribution to d{sigma}/dz is in qualitative agreement with data. Quantitative tests of the universality of color-octet matrix elements require improved knowledge of shape functions entering these calculations as well as resummation of the color-singlet contribution which accounts for much of the total cross section and also peaks near the endpoint.

• OSTI ID: 20868084
• Journal Information: Physical Review. D, Particles Fields, Journal Name: Physical Review. D, Particles Fields Journal Issue: 11 Vol. 74; ISSN PRVDAQ; ISSN 0556-2821
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
COLOR MODEL
CORRECTIONS
DIFFERENTIAL CROSS SECTIONS
DISTRIBUTION FUNCTIONS
FACTORIZATION
J PSI-3097 MESONS
MATRIX ELEMENTS
PERTURBATION THEORY
PHOTON-PROTON INTERACTIONS
PHOTOPRODUCTION
PROTONS
QUANTUM CHROMODYNAMICS
RENORMALIZATION
TOTAL CROSS SECTIONS