Conveners
New approaches to PDFs at and beyond Leading Twist
- Timothy Hobbs (Southern Methodist University)
Description
co-host: Lamiaa El Fassi
We present the results that are necessary in the ongoing lattice calculations of the gluon parton distribution functions (PDFs) within the pseudo-PDF approach. We give a classification of possible two-gluon correlator functions and identify those that contain the invariant amplitude determining the gluon PDF in the light-cone $z^2\to0$ limit. One-loop calculations have been performed in the...
The pseudo-distribution formalism is one such lattice methodology capable of extracting light-cone distributions from matrix elements of suitably constructed Euclidean non-local operators of a spacelike extent. Leveraging the distillation spatial smearing program, we extract the unpolarized isovector valence quark PDF of the nucleon via a direct 1-loop matching of the computed Ioffe-time...
We investigate the so-called Lorentz invariance relations from the standpoint of the proper definitions of partonic correlations functions resulting from factorization; that is in light the proper treatment of ultraviolet divergences. We show that there are corrections to the naive Lorentz invariance relations are nontrivial even in very simple renormalizable quantum field theories. We also...
We revisit the derivation of collinear factorization for Deep Inelastic Scattering to more faithfully represent the partonic kinematic at sub-asymptotic energy than possible in the conventional approach. We verify the validity of the obtained factorization formula by considering a diquark spectator model designed to reproduce the main features of electron-proton scattering at large $x_B$ in...
The quasi-PDF approach, proposed by Ji in 2013, is at the forefront of numerical calculation of partonic structure of strongly interacting systems from lattice QCD. This approach relies on the extraction of matrix elements of space-like operators for fast-moving hadrons. Such auxiliary quantities can be related to the light-cone PDFs through a perturbatively calculable matching coefficient. We...
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...
