Hadron tomography through Wigner distributions

Abstract

We study the Wigner functions of the nucleon which provide multidimensional images of the quark distributions in phase space and combine in a single picture all the information contained in the generalized parton distributions (GPDs) and the transverse-momentum dependent parton distributions (TMDs). In particular, we present results for the distribution of unpolarized quarks in a longitudinally polarized nucleon obtained in a light-cone constituent quark model. Treating the Wigner distribution as it was a classical distribution, we obtain the quark orbital angular momentum and compare it with alternative definitions given in terms of the GPDs and the TMDs.

Comments: 6 pages, 1 figure, 1 table, Prepared for the Third International Workshop on Transverse Polarization Phenomena in Hard Scattering (Transversity2011), Veli Lošinj, Croatia, 29 Aug - 2 Sep 2011