6533b7d3fe1ef96bd1260248
RESEARCH PRODUCT
Helicity-dependent generalized parton distributions and composite constituent quarks
Sergio ScopettaSergio ScopettaVicente Ventosubject
QuarkPhysicsNuclear and High Energy PhysicsParticle physicsNuclear TheoryHigh Energy Physics::LatticeMomentum transferQuark modelHigh Energy Physics::PhenomenologyForm factor (quantum field theory)Constituent quarkFOS: Physical sciencesFísicaPartonHelicityNuclear Theory (nucl-th)High Energy Physics - PhenomenologyHigh Energy Physics - Phenomenology (hep-ph)Nucleondescription
An approach, recently proposed to calculate the nucleon generalized parton distributions (GPDs) in a constituent quark model (CQM) scenario, in which the constituent quarks are taken as complex systems, is used to obtain helicity-dependent GPDs. They are obtained from the wave functions of the non relativistic CQM of Isgur and Karl, convoluted with the helicity-dependent GPDs of the constituent quarks themselves. The latter are modelled by using the polarized structure functions of the constituent quark, the double distribution representation of GPDs, and a phenomenological constituent quark form factor. The present approach permits to access a kinematical range corresponding to both the Dokshitzer-Gribov-Lipatov-Altarelli-Parisi and the Efremov-Radyushkin-Brodsky-Lepage regions, for small values of the momentum transfer and of the skewedness parameter. In this kinematical region, the present calculation represents a prerequisite for the evaluation of cross sections relevant to deeply virtual Compton scattering. In particular, we have calculated the leading twist helicity-dependent GPD \tilde H and, from our expressions, its general relations with the non relativistic definition of the axial form factor and with the leading twist polarized quark density are consistently recovered.
| year | journal | country | edition | language |
|---|---|---|---|---|
| 2004-10-13 |