Wigner Functions and Parton Distributions of the nucleon

by Barbara Pasquini (University of Pavia)

Monday 27 Apr 2015, 14:30 → 16:00 Europe/Rome

Aula Conversi (Dipartimento di Fisica - Ed. G.Marconi)

I will discuss the Wigner functions of the nucleon which provide multidimensional images of the quark distributions in phase space. They depend on both the transverse position and the three-momentum of the quark relative to the nucleon, and therefore combine in a single picture all the information contained in the generalized parton distributions and the transverse-momentum dependent parton distributions. I will consider a few example of Wigner functions within light-front quark models, discussing the role of the quark orbital angular momentum in shaping the nucleon and its correlations with the quark and nucleon polarizations. The quark orbital angular momentum is also calculated from the phase-space average of the orbital angular momentum operator weighted with the Wigner distribution of unpolarized quarks in a longitudinally polarized nucleon. The corresponding results are compared with alternative definitions of the quark orbital angular momentum, as given in terms of generalized parton distributions.