Double distributions and evolution equations

Journal Article · Fri May 01 04:00:00 EDT 1998 · Phys.Rev. D59 (1999) 014030

DOI:https://doi.org/10.1103/PhysRevD.59.014030· OSTI ID:755926

Radyushkin, A V

Applications of perturbative QCD to deeply virtual Compton scattering and hard exclusive meson electroproduction processes require a generalization of usual parton distributions for the case when long-distance information is accumulated in nonforward matrix elements < p{prime} {vert_bar}O(0,z){vert_bar}p > of quark and gluon light-cone operators. In their previous papers the authors used two types of nonperturbative functions parameterizing such matrix elements: double distributions F(x,y;t) and nonforward distribution functions F{sub {zeta}}(X;t). Here they discuss in more detail the double distributions (DD's) and evolution equations which they satisfy. They propose simple models for F(x,y;t=0) DD's with correct spectral and symmetry properties which also satisfy the reduction relations connecting them to the usual parton densities f(x). In this way, they obtain self-consistent models for the {zeta}-dependence of nonforward distributions. They show that, for small {zeta}, one can easily obtain nonforward distributions (in the X > {zeta} region) from the parton densities: F{sub {zeta}} (X;t=0) {approx} f(X{minus}{zeta}/2).

• 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: 755926
• Report Number(s): DOE/ER/40150-1500; JLAB-THY-98-16; hep-ph/9805342
• Journal Information: Phys.Rev. D59 (1999) 014030, Journal Name: Phys.Rev. D59 (1999) 014030
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
COMPTON EFFECT
ELECTROPRODUCTION
FUNCTIONS
MATRIX ELEMENTS
MESONS
PARTONS
PERTURBATION THEORY
QUANTUM CHROMODYNAMICS
SELF-CONSISTENT FIELD