Eur. Phys. J. C (2016) 76: 597
https://doi.org/10.1140/epjc/s10052-016-4445-6

Special Article - Tools for Experiment and Theory

Small-x resummation from HELL

¹ Rudolf Peierls Centre for Theoretical Physics, University of Oxford, 1 Keble Road, Oxford, England, UK
² University at Buffalo, The State University of New York, Buffalo, NY, 14260-1500, USA
³ Higgs Centre for Theoretical Physics, School of Physics and Astronomy, The University of Edinburgh, Edinburgh, EH9 3JZ, Scotland, UK

^* e-mail: smarzani@buffalo.edu

Received: 12 July 2016
Accepted: 19 October 2016
Published online: 2 November 2016

Abstract

Small-x logarithmic enhancements arising from high-energy gluon emissions affect both the evolution of collinearly-factorized parton densities and partonic coefficient functions. With the higher collider energy reached by the LHC, the prospect of a future high-energy collider, and the recent deep-inelastic scattering (DIS) results at small-x from HERA, providing phenomenological tools for performing small-x resummation has become of great relevance. In this paper we discuss a framework to perform small-x resummation for both parton evolution and partonic coefficient functions and we describe its implementation in a computer code named High-Energy Large Logarithms (HELL). We present resummed and matched results for the DGLAP splitting functions and, as a proof of principle, for the massless structure functions in DIS. Furthermore, we discuss the uncertainty from subleading terms on our results.