DGLAP evolution at N 3 LO with the candia algorithm
Casey Hampson, Marco Guzzi · Physical review. D/Physical review. D. · 2026
We present a generalization of the x -space andia algorithm to next-to-next-to-next-to-leading order ( N 3 LO ) accuracy in quantum chromodynamics (QCD) for solving the Dokshitzer-Gribov-Lipatov-Altarelli-Parisi (DGLAP) evolution equations for unpolarized parton densities in the nucleon. The algorithm is based on logarithmic expansions of the solution and can be extended to all orders in QCD. An expansion equivalent to the exact solution of the DGLAP equation at N 3 LO is presented in the non-singlet sector. Results for approximate N 3 LO parton distribution functions, evolved using the most recent approximations to the N 3 LO DGLAP splitting functions, are provided for benchmarking. The new version of the code, andia-v2, is publicly available [itub, andia-v2, (2025).].