A Rederivation of the Spin-dependent Next-to-leading Order Splitting Functions

TL;DR

The paper re-derives the spin-dependent next-to-leading order splitting functions using the Curci–Furmanski–Petronzio approach in the HVBM γ5 scheme, providing an independent check of Mertig and van Neerven. By exploiting the unpolarized results for real-emission graphs and carefully treating spurious poles in the light-like axial gauge, the author reconstructs the polarized ΔΓ and extracts the NLO splitting functions. A factorization-scheme transformation is employed to align with MSbar, and the final results agree with the recent Neerven calculations. This work validates the polarized NLO QCD evolution and demonstrates the efficacy of the CF-P approach in a polarized context.

Abstract

We perform a new calculation of the polarized next-to-leading order splitting functions, using the method developed by Curci, Furmanski and Petronzio. We confirm the results of the recent calculation by Mertig and van Neerven.