Difference: CERNYellowReportPageAt14TeV (21 vs. 22)

Revision 222017-04-12 - ReiTanaka

Line: 1 to 1
 
META TOPICPARENT name="LHCHXSWG"
<!--  
Line: 264 to 264
 
  • Photon-induced contribution of O(1%) or below
    • NOT included for total cross section (agrees with CERN Report 3 numbers).
    • Included in cross sections for dedicated ZH→llH,ννH (l=e,μ or τ) processes (we strongly recommend to use these numbers for dedicated analyses).
Changed:
<
<
  • For separate cross sections and associated QCD scale uncertainties in qq/qg→ZH and gg→ZH, use
    • σ(qq/qg→ZH) = σ(pp→ZH)@(NNLO QCD + NLO EW, NLO+NLL QCD gg→ZH) - σ(gg→ZH)@(NLO+NLL QCD),
    • Separate QCD scale uncertainties are σ(qq/qg→ZH) or on σ(gg→ZH) are calculated with VH@NNLO program.
>
>

gg→ZH Cross Section

  • ZH production has two distinct sources of gg→ZH:
    1. a genuine NNLO contribution to what called “Drell-Yan-like”, where ZH is accompanied by two-parton radiation, gg→HZ+qqbar.
    2. top- and bottom-loop induced contribution without any additional partons in the final state.
  • What is usually meant by gg→HZ below is 2) above.
  • The statement that “all but gg→HZ” is the same as “qq- and qg-initiated” is correct only through NLO QCD.
  • For separate cross sections and associated QCD scale uncertainties in qq/qg→ZH(+gg→HZ+qqbar) and gg→ZH for NLO/LO MC normalization, use
    • σ(all but gg→ZH) = σ(pp→ZH)@(NNLO QCD + NLO EW, NLO+NLL QCD gg→ZH) - σ(gg→ZH)@(NLO+NLL QCD),
    • Separate QCD scale uncertainties are σ(all but gg→ZH) or on σ(gg→ZH) are calculated with VH@NNLO program.
 
    • For MH=125.0 GeV and at √s=14 TeV,
Process Cross Section (pb) +QCD Scale % -QCD Scale % ±(PDF+αs) % ±PDF % ±αs %
pp→ZH 0.9861 +3.8% -3.3% ±1.6% ±1.3% ±1.0%
Changed: <
<
qq/qg→ZH (all but gg→ZH) 0.8418 +0.4% -0.7% ±1.8% ±1.6% ±0.8%
>
>
qq/qg→ZH, gg→HZ+qqbar (all but gg→ZH) 0.8418 +0.4% -0.7% ±1.8% ±1.6% ±0.8%
 
gg→ZH 0.1443 +25.1% -18.8% ±2.4% ±1.7% ±1.7%
 
This site is powered by the TWiki collaboration platform Powered by PerlCopyright &© 2008-2019 by the contributing authors. All material on this collaboration platform is the property of the contributing authors.
Ideas, requests, problems regarding TWiki? Send feedback