Speaker
Description
Parton distribution functions (PDFs) are important quantities in hadron physics, quantifying the momentum distribution of quarks and gluons inside hadrons. In this talk, we present a lattice QCD calculation of twist-3 $g_T(x)$ and $h_L(x)$ PDFs of the proton, that are of great interest in phenomenology, as they encode new information on quark-gluon-quark correlations, accessible experimentally in inclusive, semi-inclusive DIS and Drell-Yan processes.
In our work, we employ the quasi-distribution formalism and compute correlation functions between two boosted proton states, that are eventually matched onto light-cone distributions through perturbative matching formulae developed in Large Momentum Effective Theory (LaMET). We use an ensemble of gauge configurations with two degenerate light quarks, a strange and a charm quark $(N_f= 2+1+1)$ within the twisted mass formulation, with lattice spacing $a=0.093$ fm and pion mass $M_{\pi}=270$ MeV. The proton is boosted to 0.83, 1.25 and 1.67 GeV.
Twist-3 PDFs are compared to their twist-2 counterparts PDFs and, for the first time, the Wandzura-Wilczek approximation is tested using an ab initio calculation within lattice QCD.
