# PDF4LHC recommendations for LHC Run II

Jon Butterworth, Stefano Carrazza, Amanda Cooper-Sarkar, Albert de Roeck, Joel Feltesse, Stefano Forte, Jun Gao, Sasha Glazov, Joey Huston, Zahari Kassabov, Ronan McNulty, Andreas Morsch, Pavel Nadolsky, Voica Radescu, Juan Rojo, Robert S. Thorne

## Abstract

We provide an updated recommendation for the usage of sets of parton distribution functions (PDFs) and the assessment of PDF and PDF+$\alpha_s$ uncertainties suitable for applications at the LHC Run II. We review developments since the previous PDF4LHC recommendation, and discuss and compare the new generation of PDFs, which include substantial information from experimental data from the Run I of the LHC. We then propose a new prescription for the combination of a suitable subset of the available PDF sets, which is presented in terms of a single combined PDF set. We finally discuss tools which allow for the delivery of this combined set in terms of optimized sets of Hessian eigenvectors or Monte Carlo replicas, and their usage, and provide some examples of their application to LHC phenomenology.
Original language English Journal of Physics G. Nuclear and Particle Physics https://doi.org/10.1088/0954-3899/43/2/023001 Published - 13 Oct 2015

### Bibliographical note

65 pages, 20 figures, additional benchmark comparison plots available from http://www.hep.ucl.ac.uk/pdf4lhc/mc2h-gallery/website. v2, accepted for publication in Journal of Physics G

• hep-ph
• hep-ex