English

Two-Loop DGLAP Splitting Functions from Light Cone Perturbation Theory

High Energy Physics - Phenomenology 2026-01-16 v1 Nuclear Theory

Abstract

We perform a two-loop calculation in Light Cone Perturbation Theory (LCPT) to evaluate the next-to-leading order nonsinglet splitting function. Our calculation demonstrates the methodology and feasibility of performing higher order calculations in LCPT. Since in Hamiltonian perturbation theory the longitudinal k+k^+ momentum is always positive, poles in 1/k+1/k^+ can be regularized by a simple cutoff which cancels in physical results, without any associated ambiguities. For transverse momentum integrals we use dimensional regularization. Developing methods for loop calculations in LCPT paves the way for a systematical, automatizable procedure for precision calculations in this framework with a transparent physical partonic interpretation. This can provide a standard framework in higher order calculations in the gluon saturation regime of QCD.

Keywords

Cite

@article{arxiv.2601.10374,
  title  = {Two-Loop DGLAP Splitting Functions from Light Cone Perturbation Theory},
  author = {Tuomas Lappi and Risto Paatelainen and Mikko Seppälä},
  journal= {arXiv preprint arXiv:2601.10374},
  year   = {2026}
}

Comments

15 pages, 4 figures, 3 appendices

R2 v1 2026-07-01T09:05:50.877Z