Deeply virtual Compton scattering at small x

Journal Article · Tue Feb 01 04:00:00 EST 2000 · Physics Review

OSTI ID:754541

Balitsky, I; Kuchina, E

The authors calculate the cross section of the deeply virtual Compton scattering at large energies and intermediate momentum transfers. In recent years the study of the deeply virtual Compton scattering (DVCS) became one of the most popular topics in QCD due to the fact that it is determined by skewed parton distributions which generalize usual parton densities introduced by Feynman. These new probes of the nucleon structure are accessible in exclusive processes such as DVCS and potentially they can give more information than the traditional parton densities. In this paper the authors consider the small-x DVCS where the energy of the incoming virtual photon E is very large in comparison to its virtuality Q{sup 2}. To be specific, they calculate the DVCS amplitude in the region s >> Q{sup 2} >> -t >> m{sup 2} where s = 2mE, m is the nucleon mass, and t is the momentum transfer. The DVCS in this region is a semihard process which can be described by the BFKL (Balitsky-Fadin-Kuraev-Lipatov) pomeron. It turns out that at large momentum transfer the coupling of the BFKL pomeron to the nucleon is essentially equal to the Dirac form factor of the nucleon F{sub 1}(t), so the DVCS amplitude in the region can be calculated without any model assumptions. The results obtained in this region can be used for the estimates of the amplitude at experimentally accessible energies where one or more conditions in Eq. (1) are relaxed. To be specific, they have in mind the HERA kinematics where x {approx} 10{sup -2} {divided_by} 10{sup -4}, Q{sup 2} {ge} 6 GeV{sup 2}, and -t {approx} 1 {divided_by} 5 GeV{sup 2}. Since there are only model predictions for the small-x DVCS in current literature, even the approximate calculations of the cross section in QCD are very timely.

• Research Organization: Thomas Jefferson National Accelerator Facility, Newport News, VA (US)
• Sponsoring Organization: USDOE Office of Energy Research (ER) (US)
• DOE Contract Number: AC05-84ER40150
• OSTI ID: 754541
• Report Number(s): DOE/ER/40150-1381; JLAB-THY-00-05; hep-ph/0002195
• Journal Information: Physics Review, Journal Name: Physics Review Journal Issue: 62 Vol. D
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
AMPLITUDES
COMPTON EFFECT
COMPTON SCATTERING
CROSS SECTIONS
DIRAC FORM FACTORS
MOMENTUM TRANSFER
NUCLEONS
PARTONS
PHOTONS
POMERANCHUK PARTICLES
PROBES
QCD
QUANTUM CHROMODYNAMICS