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The NLO corrections to DIS-like process, initiated by gauge-invariant operator tr[G_{mu nu}G^{mu nu}] (Where G_{mu nu} is field-strength tensor of QCD) had been studied in Refs. [1,2], including one-loop and real-emission NLO corrections. This "Higgs-initiated DIS" process is a simplest small-x physics process for which it is most convenient to study problem of convergence of perturbative series, which arises in High-Energy Factorization (kT-factorization) at NLO. In the standard BFKL-type NLO calculation (called "MRK-subtraction" in Ref. [2]) the usual over-subtraction problem in collinear region of NLO correction is found. An improved "modified-MRK (MMRK) approximation", interpolating between MRK and collinear limits of scattering amplitude, is proposed to solve the over-subtraction problem. The evolution equation based on MMRK approximation is proposed [2] and studied. The improved physical behavior of NLO correction with MMRK subtraction is demonstrated [2].
References:
[1] M.A. Nefedov, Computing one-loop corrections to effective vertices with two scales in the EFT for Multi-Regge processes in QCD, Nucl. Phys. B 946, 114715 (2019) doi:10.1016/j.nuclphysb.2019.114715 [arXiv:1902.11030 [hep-ph]].
[2] M.A.Nefedov, Towards stability of NLO corrections in High-Energy Factorization via Modified Multi-Regge Kinematics approximation, JHEP 08, 055 (2020)
doi:10.1007/JHEP08(2020)055 [arXiv:2003.02194 [hep-ph]].
