Coordinate-space picture and $x \to 1$ singularities at fixed $k_\perp$

Abstract

We discuss ongoing progress towards precise characterizations of parton distributions at fixed transverse momentum, focusing on matrix elements in coordinate space and the treatment of endpoint singularities.

Figures (3)

• Figure 1: Quark distribution function in the target of momentum p.
• Figure 2: Cut-off regularization for the quark matrix element.
• Figure 3: Matrix element with subtractive regularization.