18-22 October 2021
Matsue, Shimane Prefecture, Japan
Asia/Tokyo timezone

Lattice results on twist-3 parton distributions

21 Oct 2021, 07:54
Room 601 (Kunibiki Messe)

Room 601

Kunibiki Messe

Parallel Session Presentation Transverse momentum structure (TMD) Joint TMD - GPD - HELCITY - Future session US timezone


Aurora Scapellato (Temple University)


Twist-3 distributions are very important quantities for the study of hadron structure, and presently they are poorly known experimentally. In this talk, we present the first-ever results on the proton iso-vector twist-3 PDFs $g_T(x)$ and $h_L(x)$, obtained from lattice QCD. We employ the quasi-PDF approach, which is based on computation of correlation functions between two boosted proton states at finite momentum, that are eventually matched to the light-cone distributions through perturbative matching formulae, that we developed specifically for twist-3 PDFs.
Our calculations are performed on a gauge ensemble with two degenerate light quarks, a strange and a charm quark $(N_f= 2 +1 +1)$, with lattice spacing $a=0.093$ fm and pion mass $M_\pi=270$ MeV.
The proton is boosted to 0.83 GeV, 1.25 GeV and 1.67 GeV to check momentum convergence. On the same ensemble we also extract the twist-2 counterparts and test the Wandzura-Wilczek approximation.
Extending the methodologies developed for PDFs, we also present preliminary results for twist-3 GPDs.

Primary authors

Dr Shohini Bhattacharya (Temple University) Prof. Krzysztof Cichy (Adam Mickiewicz University) Prof. Martha Constantinou (Temple University) Mr Jack Dodson (Temple University) Prof. Andreas Metz (Temple University) Aurora Scapellato (Temple University) Dr Fernanda Steffens (Bonn University)

Presentation Materials