# 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

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recommendations
partons
distribution functions
replicas
phenomenology
set theory
delivery
eigenvectors

### 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

### Cite this

Butterworth, J., Carrazza, S., Cooper-Sarkar, A., Roeck, A. D., Feltesse, J., Forte, S., ... Thorne, R. S. (2015). PDF4LHC recommendations for LHC Run II. Journal of Physics G. Nuclear and Particle Physics. https://doi.org/10.1088/0954-3899/43/2/023001
Butterworth, Jon ; Carrazza, Stefano ; Cooper-Sarkar, Amanda ; Roeck, Albert de ; Feltesse, Joel ; Forte, Stefano ; Gao, Jun ; Glazov, Sasha ; Huston, Joey ; Kassabov, Zahari ; McNulty, Ronan ; Morsch, Andreas ; Nadolsky, Pavel ; Radescu, Voica ; Rojo, Juan ; Thorne, Robert S. / PDF4LHC recommendations for LHC Run II. In: Journal of Physics G. Nuclear and Particle Physics. 2015.
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title = "PDF4LHC recommendations for LHC Run II",
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.",
keywords = "hep-ph, hep-ex",
author = "Jon Butterworth and Stefano Carrazza and Amanda Cooper-Sarkar and Roeck, {Albert de} and Joel Feltesse and Stefano Forte and Jun Gao and Sasha Glazov and Joey Huston and Zahari Kassabov and Ronan McNulty and Andreas Morsch and Pavel Nadolsky and Voica Radescu and Juan Rojo and Thorne, {Robert S.}",
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",
year = "2015",
month = "10",
day = "13",
doi = "10.1088/0954-3899/43/2/023001",
language = "English",
journal = "Journal of Physics G. Nuclear and Particle Physics",
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Butterworth, J, Carrazza, S, Cooper-Sarkar, A, Roeck, AD, Feltesse, J, Forte, S, Gao, J, Glazov, S, Huston, J, Kassabov, Z, McNulty, R, Morsch, A, Nadolsky, P, Radescu, V, Rojo, J & Thorne, RS 2015, 'PDF4LHC recommendations for LHC Run II' Journal of Physics G. Nuclear and Particle Physics. https://doi.org/10.1088/0954-3899/43/2/023001

PDF4LHC recommendations for LHC Run II. / Butterworth, Jon; Carrazza, Stefano; Cooper-Sarkar, Amanda; Roeck, Albert de; Feltesse, Joel; Forte, Stefano; Gao, Jun; Glazov, Sasha; Huston, Joey; Kassabov, Zahari; McNulty, Ronan; Morsch, Andreas; Nadolsky, Pavel; Radescu, Voica; Rojo, Juan; Thorne, Robert S.

In: Journal of Physics G. Nuclear and Particle Physics, 13.10.2015.

TY - JOUR

T1 - PDF4LHC recommendations for LHC Run II

AU - Butterworth, Jon

AU - Carrazza, Stefano

AU - Cooper-Sarkar, Amanda

AU - Roeck, Albert de

AU - Feltesse, Joel

AU - Forte, Stefano

AU - Gao, Jun

AU - Glazov, Sasha

AU - Huston, Joey

AU - Kassabov, Zahari

AU - McNulty, Ronan

AU - Morsch, Andreas

AU - Rojo, Juan

AU - Thorne, Robert S.

N1 - 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

PY - 2015/10/13

Y1 - 2015/10/13

N2 - 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.

AB - 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.

KW - hep-ph

KW - hep-ex

U2 - 10.1088/0954-3899/43/2/023001

DO - 10.1088/0954-3899/43/2/023001

M3 - Article

JO - Journal of Physics G. Nuclear and Particle Physics

JF - Journal of Physics G. Nuclear and Particle Physics

SN - 0954-3899

ER -

Butterworth J, Carrazza S, Cooper-Sarkar A, Roeck AD, Feltesse J, Forte S et al. PDF4LHC recommendations for LHC Run II. Journal of Physics G. Nuclear and Particle Physics. 2015 Oct 13. https://doi.org/10.1088/0954-3899/43/2/023001