[Theory-seminars] Theory seminar Mon. Jan 30th, L102 - Anatoly Radyushkin

[Raul Briceno]

Theory Center Seminar
Monday, Jan 30th, 2017
1:00 p.m.
Room L102

Anatoly Radyushkin (ODU/JLab)
Title: Nonperturbative Evolution of Parton Quasi-Distributions

Abstract:
Using the formalism of parton virtuality distribution functions (VDFs) we establish a connection between the transverse momentum dependent distributions (TMDs) and quasi-distributions (PQDs) introduced recently by X. Ji for lattice QCD extraction of parton distributions. We build models for PQDs from the VDF-based models for soft TMDs, and analyze the P_z dependence of the resulting PQDs. We observe a strong nonperturbative evolution of PQDs for small and moderately large values of P_z reflecting the transverse momentum dependence of TMDs. Thus, the study of PQDs on the lattice in the domain of strong nonperturbative effects opens a new perspective for investigation of the 3-dimensional hadron structure. A similar analysis is done for the pion distribution amplitude. As there are many models claimed to describe the primordial shape of the pion DA, we present the $p_3$-evolution patterns for models producing some popular proposals: Chernyak-Zhitnitsky, flat and asymptotic DAs. Our results may be used as a guide for future studies of the pion distribution amplitude on the lattice using the quasi-distribution approach.