MIT bag model inspired partonic transverse momentum distribution for prompt photon production in pp collisions

Journal Article · Mon Sep 01 04:00:00 EDT 2008 · Physical Review. D, Particles Fields

DOI:https://doi.org/10.1103/PHYSREVD.78.054023· OSTI ID:21250731

Diakonos, F K; Kaplis, N K; Maintas, X N ^[1]

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1. Department of Physics, University of Athens, GR-15771 Athens (Greece)

We consider the prompt photon production in pp collisions using, within the framework of perturbative QCD, a non-Gaussian distribution for the transverse momentum distribution of the partons inside the proton. Our description adopts the widely used in the literature factorization of the partonic momentum distribution into longitudinal and transverse components. It is argued that the non-Gaussian distribution of the intrinsic transverse momenta of the partons is dictated by the asymptotic freedom as well as the 3D confinement of the partons in the proton. To make this association more transparent we use the MIT bag model, which plainly incorporates both properties (asymptotic freedom, confinement), in order to determine in a simplified way the partonic transverse momentum distribution. A large set of data from six different experiments have been fitted with this simple description using as a single free parameter the mean partonic transverse momentum <k{sub T}>. Surprisingly enough, a perfect fit of the experimental data turns out to require <k{sub T}> values which are compatible with Heisenberg's uncertainty relation for the proton and decrease almost smoothly as a function of the scaled variable z=(p{sub T}/{radical}(s)), where p{sub T} is the transverse momentum of the final photon and {radical}(s) is the beam energy in the center of mass frame. Our analysis indicates that asymptotic freedom and 3D confinement may influence significantly the form of the partonic transverse momentum distribution leaving an imprint on the pp{yields}{gamma}+X cross section.

• OSTI ID: 21250731
• Journal Information: Physical Review. D, Particles Fields, Journal Name: Physical Review. D, Particles Fields Journal Issue: 5 Vol. 78; ISSN PRVDAQ; ISSN 0556-2821
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
ASYMPTOTIC SOLUTIONS
BAG MODEL
BEAMS
CENTER-OF-MASS SYSTEM
CONFINEMENT
CROSS SECTIONS
DISTRIBUTION
FACTORIZATION
GAUSS FUNCTION
PARTICLE PRODUCTION
PERTURBATION THEORY
PHOTONS
PROTON-PROTON INTERACTIONS
QUANTUM CHROMODYNAMICS
TRANSVERSE MOMENTUM