Recent developments in the constituent quark model including quark-antiquark pairs

Abstract

We present the formalism for a new generation of unquenched quark models for baryons in which the effects of quark-antiquark pairs (u anti-u, d anti-d and s anti-s) are taken into account in an explicit form via a microscopic, QCD-inspired, quark-antiquark creation mechaniscm. The present approach is an extension of the flux-tube breaking model of Geiger and Isgur in which now the contributions of quark-antiquark pairs an be studied for any initial baryon and for any flavor of the q anti-q pair. It is shown that the inclusion of q anti-q paris leads to a large contribution of orbital angular momentum to the proton spin.

5 pages, 4 figures, 2 tables, NSTAR2007, Proceedings of the 11th Workshop on the Physics of Excited Nucleons, Springer, 2008

References in corpus (6)

• Precise determination of the spin structure function ${\mathbf{g}}_1$ of the proton, deuteron and neutron
• Precision Measurements of the Nucleon Strange Form Factors at Q^2 ~0.1 GeV^2
• Flavor Asymmetry of Light Quarks in the Nucleon Sea
• Relativistic quark models of baryons with instantaneous forces
• Evidence for the Absence of Gluon Orbital Angular Momentum in the Nucleon
• Axial exchange currents and nucleon spin