Speaker
Abha Rajan
(University of Virginia)
Description
It is well known that the valence quark spins do not add up to the proton spin. We probe the partonic orbital angular momentum (OAM) contribution to the spin sum rules using the Generalized Parton Distributions(GPDs) and Generalized Transverse Momentum Distributions (GTMDs). These functions are obtained by parameterizing the QCD quark quark correlator function in different scenarios. By looking at the parametrization of the completely unintegrated correlator and finding the underlying substructure of these functions, we find the so called Lorentz Invariance Relations between collinear objects, the GPDs, and ones that depend on the partonic intrinsic transverse momentum, the GTMDs. The GTMD $F_{14}$ which describes OAM connects through these relations to the twist three GPD $\tilde{E}_{2T}$ thus allowing us to study the role of quark gluon interactions for different choices of gauge links. Other helicity combinations give rise to more LIRs which, in general, are significant for understanding the non-perturbative origin of the spin structure of the proton.
Primary author
Abha Rajan
(University of Virginia)
Co-authors
Brandon Kriesten
(University of Virginia)
Prof.
simonetta liuti
(university of virginia)
