T-odd quark–gluon–quark correlation function in the diquark model

Fragmentation Function and Nucleon Transversity Distribution in a Diquark Model

Based on a simple quark-diquark model, we propose a set of unpolarized, longitudinally polarized and transversely polarized fragmentation functions for the Λ by fitting the unpolarized Λ production data in ee annihilation. It is found that the helicity structure of the obtained Λ fragmentation functions is supported by the all available experimental data on the longitudinal Λ polarization. With...

Diquark Correlations in the Nucleon Structure Function

The nucleon structure functions are studied with a special emphasis on diquark correlations inside the nucleon. Assuming a phenomenological diquark-quark model of the nucleon at the low energy hadronic scale, we calculate the leading twist contributions to the nucleon structure functions. We take the Nambu and Jona-Lasinio model for the calculation of the quark distributions in the diquarks, an...

Nucleons in the Covariant Quark–diquark Model

We introduce diquarks as separable correlations in the two–quark Green’s function to facilitate the description of baryons as relativistic three– quark bound states. These states then emerge as solutions of Bethe– Salpeter equations for quarks and diquarks that interact via quark exchange. Approximating quark and diquark propagators by the corresponding free ones, we calculate nucleon static pr...

Electromagnetic Processes and the Diquark Model

The Diquark Model for Exclusive Reactions

The present status of the diquark model for exclusive reactions at moderately large momentum transfer is reviewed. That model is a variant of the BrodskyLepage approach in which diquarks are considered as quasi-elementary constituents of baryons. Recent applications of the diquark model, relevant to high energy physics with electromagnetic probes, are discussed.