Candia-v2: Logarithmic expansions for DGLAP evolution in $x$-space

Abstract

We present Candia-v2, an open-source software package that generalizes the $x$-space Candia algorithm to next-to-next-to-next-to-leading order (N$^{3}$LO) accuracy in Quantum Chromodynamics (QCD). The code solves the DGLAP evolution equations for unpolarized nucleon parton densities using a highly efficient logarithmic expansion technique that can be systematically extended to all orders in QCD. Candia-v2 supersedes the previous original C implementation of the algorithm with significantly increased efficiency and improved API. The software is publicly available on GitHub under the GPLv3 license.