Physical Review D
We show that quasi-parton distribution functions (quasi-PDFs) may be treated as hybrids of PDFs and primordial rest-frame momentum distributions of partons. This results in a complicated convolution nature of quasi-PDFs that necessitates using large p3 ≳ 3 GeV momenta to get reasonably close to the PDF limit. As an alternative approach, we propose using pseudo-PDFs P(x, z²3) that generalize the light-front PDFs onto spacelike intervals and are related to Ioffe-time distributions M(v, z²3), the functions of the Ioffe time v = p3z3 and the distance parameter z²3 with respect to which it displays perturbative evolution for small z3. In this form, one may divide out the z²3 dependence coming from the primordial rest-frame distribution and from the problematic factor due to lattice renormalization of the gauge link. The v dependence remains intact and determines the shape of PDFs.
Original Publication Citation
Radyushkin, A. V. (2017). Quasi-parton distribution functions, momentum distributions, and pseudo-parton distribution functions. Physical Review D, 96(3), 1-6. doi:10.1103/PhysRevD.96.034025
Radyushkin, A. V., "Quasi-Parton Distribution Fuctions, Momentum Distributions, and Pseudo-Parton Distribution Functions" (2017). Physics Faculty Publications. 78.