Light cone perturbation theory is commonly used in cross section calculations in the gluon saturation regime of high energy QCD. It provides a conceptual and calculational framework for describing the factorization of high energy dilute-dense scattering processes into the light cone wave function of the probe, and the scattering of its partonic contents of the saturated gluonic target. In recent years calculations of dilute-dense processes in the high energy saturation regime have advanced to the one-loop level. This talk describes recent work on the deep inelastic scattering cross section in the dipole picture with massive quarks. The process is very relevant for the physics of HERA and the EIC. This calculation also requires a renormalization of the quark mass, which we perform in the pole mass scheme. While the divergent parts of the mass counter-terms had been extracted already previously, the one loop cross section in a specific scheme requires one to also have the correct finite terms. Since our regularization procedure breaks 3-dimensional rotational invariance, an additional renormalization condition is needed to restore Lorentz-invariance at the one loop level.
 G. Beuf, T. Lappi, R. Paatelainen, Massive Quarks at One Loop in the Dipole Picture of Deep Inelastic Scattering, Phys.Rev.Lett. 129 (2022) 7, 072001
 G. Beuf, T. Lappi, R. Paatelainen, Massive quarks in NLO dipole factorization for DIS: Longitudinal photon, Phys.Rev.D 104 (2021) 5, 056032
 G. Beuf, T. Lappi, R. Paatelainen, Massive quarks in NLO dipole factorization for DIS: Transverse photon, Phys.Rev.D 106 (2022) 3, 034013
Webinar at https://us02web.zoom.us/j/81572103194?pwd=eE1QVWZFc1hWbWszZ2N0RW1iWHFBZz09