====== Parton distribution functions at CMS ======

This page aims to collect information about **PDFs** that are relevant for CMS. More on **cross sections** can be found [[physics:crosssections|here]], and more on **luminosity** can be found [[physics:lumi|here]] instead.
===== General =====

  * [[http://nnpdf.mi.infn.it|NNPDF Collaboration]] with [[http://nnpdf.mi.infn.it/documents/papers/|their papers]]
  * [[https://lhapdf.hepforge.org|LHAPDF library]] to evaluate PDFs, in [[https://twiki.cern.ch/twiki/bin/view/CMSPublic/SWGuideLHAPDF|CMSSW]]
  * a very nice summary about PDFs at the LHC is made in [[https://indico.cern.ch/event/667965/contributions/2787600/attachments/1584573/2504939/Rojo.pdf|these slides]] and in [[https://arxiv.org/abs/1709.04922|this paper ("The Structure of the Proton in the LHC Precision Era", 2017)]].


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{{ physics:pdfs:pdf_sets_summary.png }}
Table summarizing the available PDF sets and how to what data they were fitted (made by [[https://indico.cern.ch/event/568360/contributions/2390640/attachments/1438115/2212495/ubialiDIS2017pdfs_nobckp.pdf|M. Ubiali at DIS2017]]).
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{{ physics:pdfs:pdfs_mmht2014_nnlo_10gev.png }}
{{ physics:pdfs:pdfs_mmht2014_nnlo_10tev.png }}
MMHT 2014 NNLO PDF sets at Q^2 = 10 GeV and 10 TeV.
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===== Run I (7, 8 TeV) =====

  * MSTW 2008 PDF sets: [[https://arxiv.org/abs/0901.0002|arxiv:0901.0002]], [[http://mstwpdf.hepforge.org/plots/plots.html|plots]]
  * MMHT 2014 PDF sets: [[https://arxiv.org/abs/1412.3989|arxiv:1412.3989]]
  * PDF4LHC: [[https://twiki.cern.ch/twiki/bin/viewauth/CMS/PDF4LHC|TWiki]]
  * PDF systematics: [[https://twiki.cern.ch/twiki/bin/view/CMSPublic/SWGuideEWKUtilities#PDF_SYSTEMATICS_PDFWeightProduce| PDFWeightProducer]]
===== Run II (13 TeV) =====

==== 2016 ====

  * NNPDF2.3 NLO and NNLO PDF sets: [[https://arxiv.org/abs/1311.5887|arxiv:1311.5887]]
  * Monash 2013 tune for Pythia 8.1: [[https://arxiv.org/abs/1404.5630|arXiv:1404.5630]]
  * TuneCUETP8M1: [[https://arxiv.org/abs/1512.00815|arxiv:1512.00815]]

==== 2017  ====

  * NNPDF3.1 NLO and NNLO PDF sets: [[https://arxiv.org/abs/1311.5887|arxiv:1706.00428]], [[https://data.nnpdf.science/nnpdf31-gallery/|plots]]
  * TuneCP5 for Pythia 8: [[https://cds.cern.ch/record/2634082|CMS-GEN-17-001]]