New features in version 2 of the fastNLO project

TL;DR

The paper introduces version 2 of fastNLO, a tool that accelerates higher-order QCD cross section calculations by using interpolation tables, enabling rapid re-evaluation for different parameters in collider physics analyses.

Contribution

It presents new features and improvements in fastNLO version 2, expanding its capabilities for faster and more flexible QCD cross section computations.

Findings

Enhanced interpolation algorithms for faster computations

Broader range of available tables for various collider experiments

Increased adoption in experimental and global PDF analyses

Abstract

Standard methods for higher-order calculations of QCD cross sections in hadron-induced collisions are time-consuming. The fastNLO project uses multi-dimensional interpolation techniques to convert the convolutions of perturbative coefficients with parton distribution functions and the strong coupling into simple products. By integrating the perturbative coefficients for a given observable with interpolation kernels, fastNLO can store the results of the time-consuming folding integrals in tables, which subsequently are used for very fast rederivations of the same observable for arbitrary parton distribution functions, different scale choices, or alpha_s(M_Z). Various tables with code for their evaluation are available for numerous jet measurements at the LHC, the TeVatron, and HERA. FastNLO is used in publications of experimental results by the ATLAS, CMS, CDF, D0, and H1 collaborations, and in all recent global PDF analyses by MSTW, CTEQ, and NNPDF. This article focuses on developments implemented in the new version 2 of fastNLO, enhancing and broadening its functionality.