Dilepton production near partonic threshold in transversely polarized pp collisions

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

DOI:https://doi.org/10.1103/PhysRevD.71.114007· OSTI ID:20709452

Shimizu, Hirotaka ^[1]; Sterman, George ^[2]; Vogelsang, Werner ^[3]; Yokoya, Hiroshi ^[4]

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1. Department of Physics, Hiroshima University, Higashi-Hiroshima 739-8526 (Japan)
2. C.N. Yang Institute for Theoretical Physics, Stony Brook University, Stony Brook, New York 11794-3840 (United States)
3. Physics Department, Brookhaven National Laboratory, Upton, New York 11973 (United States) and RIKEN BNL Research Center, Brookhaven National Laboratory, Upton, New York 11973 (United States)
4. Department of Physics, Hiroshima University, Higashi-Hiroshima 739-8526 (Japan) and Physics Department, Brookhaven National Laboratory, Upton, New York 11973 (United States) and RIKEN BNL Research Center, Brookhaven National Laboratory, Upton, New York 11973 (United States)

It has recently been suggested that collisions of transversely polarized protons and antiprotons at the GSI could be used to determine the nucleon's transversity densities from measurements of the double-spin asymmetry for the Drell-Yan process. We analyze the role of higher-order perturbative QCD corrections in this kinematic regime, in terms of the available fixed-order contributions as well as of all-order soft-gluon resummations. We find that the combined perturbative corrections to the individual unpolarized and transversely polarized cross sections are large. We trace these large enhancements to soft-gluon emission near partonic threshold, and we suggest that with a physically motivated cutoff enhancements beyond lowest order are moderated relative to resummed perturbation theory, but still significant. The unpolarized dilepton cross section for the GSI kinematics may therefore provide information on the relation of perturbative and nonperturbative dynamics in hadronic scattering. The spin asymmetry turns out to be rather robust, relatively insensitive to higher orders, resummation, and the cutoffs.

• OSTI ID: 20709452
• Journal Information: Physical Review. D, Particles Fields, Journal Name: Physical Review. D, Particles Fields Journal Issue: 11 Vol. 71; ISSN PRVDAQ; ISSN 0556-2821
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
ANTIPROTONS
ASYMMETRY
CORRECTIONS
DENSITY
DRELL MODEL
GLUONS
INCLUSIVE INTERACTIONS
PARTON MODEL
PARTONS
PERTURBATION THEORY
POLARIZATION
PROTON-PROTON INTERACTIONS
QUANTUM CHROMODYNAMICS
SPIN