English

Dipole-pion cross section in the saturation regime

High Energy Physics - Phenomenology 2025-07-16 v2

Abstract

The scale-dependent dipole-pion cross section is analyzed as a function of the dipole size rr and the impact parameter bb. This analysis relies on the Dokshitzer-Gribov-Lipatov-Altarelli-Parisi (DGLAP) evolution equation in μ1/r+μ0{\mu}{\sim} 1/r +{\mu}_{0} at the next-to-leading order (NLO) approximation, with a specific initial condition at μ0{\mu}_{0}. The dipole-pion cross section at small Bjorken variable β\beta is being considered over a wide range of transverse separations rr. Using the Laplace transformation technique, we describe the determination of the dipole-pion cross section based on the gluon distribution at the initial scale μ0{\mu}_{0} within a kinematic region characterized by low values of the Bjorken variable β\beta. We found that geometric scaling for the dipole-pion cross section holds approximately within a wide kinematic region of rQsrQ_{s}. The cross section saturates at large dipole sizes.

Keywords

Cite

@article{arxiv.2504.12837,
  title  = {Dipole-pion cross section in the saturation regime},
  author = {G. R. Boroun and B. Z. Kopeliovich},
  journal= {arXiv preprint arXiv:2504.12837},
  year   = {2025}
}
R2 v1 2026-06-28T23:01:52.318Z