====== Cross sections at CMS ======

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

Get cross sections for particular CMS samples here:

  * [[https://cms-gen-dev.cern.ch/xsdb|cross section database (XSDB) for CMS samples]], e.g. for [[https://cms-gen-dev.cern.ch/xsdb/?columns=67108863&currentPage=0&pageSize=10&searchQuery=DAS%3DDYJetsToLL_M-.%2A50_Tune|Drell-Yan]]
  * [[https://twiki.cern.ch/twiki/bin/view/CMS/SummaryTable1G25ns|summary table for 2016 samples]]
  * [[https://twiki.cern.ch/twiki/bin/view/CMS/TauIDMeasurementsHelp#2017_measurements_MC2017_v2_samp|summary table for 2017 samples]], [[https://ineuteli.web.cern.ch/ineuteli/crosssections/2017/|cross-check]]
  * calculate for samples with [[https://twiki.cern.ch/twiki/bin/view/CMS/HowToGenXSecAnalyzer| GenXSecAnalyzer]] (CMSSW), see [[physics:crosssections:GenXSecAnalyzer|this example of useage]]
===== Predicted from theory =====


==== Standard Model processes ====

  * [[https://twiki.cern.ch/twiki/bin/viewauth/CMS/StandardModelCrossSectionsat13TeV|13 TeV summary (CMS TWiki)]]
  * [[https://twiki.cern.ch/twiki/bin/view/LHCPhysics/TtbarNNLO|top quark pair production (NNLO+NNLL, CMS TWiki)]] with [[http://pdg.lbl.gov/2017/tables/rpp2017-sum-gauge-higgs-bosons.pdf|W boson branching fractions (PDG 2017)]], such that:<code>
TTTo2L2Nu:        BR(dilep)   = 10.6%       831.76 pb * (3*0.1086)^2        =  88.2877 pb
TTToHadronic:     BR(had)     = 45.4%   =>  831.76 pb * (0.6741)^2          = 377.9607 pb
TTToSemiLeptonic: BR(semilep) = 43.9%       831.76 pb * (2*3*0.1086*0.6741) = 365.3452 pb
</code>
  * [[https://twiki.cern.ch/twiki/bin/view/LHCPhysics/SingleTopRefXsec|single top production (5FS NLO, CMS TWiki)]]
==== Higgs production ====
  * [[https://twiki.cern.ch/twiki/bin/view/LHCPhysics/CrossSections|LHC Higgs Cross Section Working Group]] ([[https://twiki.cern.ch/twiki/bin/view/LHCPhysics/LHCHXSWGCrossSectionsFigures|figures]])
  * [[https://twiki.cern.ch/twiki/bin/view/LHCPhysics/CERNYellowReportPageAt8TeV|LHC Standard Model Higgs production cross section values at 8 TeV]] and [[https://twiki.cern.ch/twiki/bin/view/LHCPhysics/CERNYellowReportPageAt13TeV|at 13 TeV]] which are published in the appendices of the [[https://arxiv.org/pdf/1610.07922.pdf|Higgs Handbook Volume 4 (CERN Yellow Report)]]

<WRAP group>
<WRAP column 5%>
\\
</WRAP>
<WRAP column 80% centeralign>
**Table**: Higgs cross sections in proton collisions at LHC. Source: [[https://arxiv.org/pdf/1610.07922.pdf|Higgs Handbook Volume 4]], Chapter III, Appendix B-D: Table 191 (p. 696, ggH), Table 205 (p. 710, VBF), Table 223 (p. 730, WH), Table 225 (p. 732, ZH), Table 231 (p. 740, ttH, see also Chapter I.6 p 153) and Table 247 (p. 760, bbH).
^  process  ^    7 TeV   ^    8 TeV   ^   13 TeV   ^   14 TeV   ^
|    ggH    |  16.85     |  21.42     |  48.57     |  54.67     |
|    VBF    |  1.276     |  1.650     |  3.925     |  4.445     |
|     WH    |  0.57730   |  0.70250   |  1.37300   |  1.51400   |
|     ZH    |  0.33910   |  0.42070   |  0.88370   |  0.98580   |
|    bbH    |  0.15520   |  0.20210   |  0.48800   |  0.55290   |
|    ttH    |  0.08629   |  0.1295    |  0.4987    |  0.6037    |
|     tH    |  0.001226  |  0.001869  |  0.007425  |  0.009010  |
^    sum    ^   19.29    ^   24.53    ^   55.75    ^  62.78     ^
</WRAP>
<WRAP column 5%>
\\
</WRAP>
</WRAP>

<WRAP group>
<WRAP column 14%>
\\
</WRAP>
<WRAP column 65% centeralign>
{{ higgs_crosssections_vs_energy.png }}
</WRAP>
<WRAP column 14%>
\\
</WRAP>
</WRAP>



===== Measured =====

  * [[https://twiki.cern.ch/twiki/bin/view/CMSPublic/PhysicsResultsCombined|summary of measurements at CMS]]
  * top pair production measurements at CMS: [[https://twiki.cern.ch/twiki/bin/view/CMSPublic/PhysicsResultsTOPSummaryFigures|summary]]


===== Summary =====

Summaries of cross sections measurements by CMS are found here:
https://twiki.cern.ch/twiki/bin/view/CMSPublic/PhysicsResultsCombined

{{ cross_sections_summary_-_cms.png }}

\\
Summaries of cross sections by James Stirling are found here:
http://www.hep.ph.ic.ac.uk/~wstirlin/plots/plots.html


<WRAP group>
<WRAP column 14%>
\\
</WRAP>
<WRAP column 65% centeralign>
{{ cross_sections_summary_-_stirling.png }}
</WRAP>
<WRAP column 14%>
\\
</WRAP>
</WRAP>