WG1+ttH subgroup meeting

Monday 9 Nov 2015, 17:00 → 18:00 Europe/Zurich

CERN

Summary of meeting with ttH 9.11.2015

Present: WG1 conveners (Bruce, Massimiliano, Pasquale, Robert)+ Stefano, Laura, Stefan for ttH conveners

 

- Stefano presents the ongoing activities of the ttH subgroup in view of the YR4:

About 9 contributions are expected for a total of about 40 pages.

Contributions are described here:

https://twiki.cern.ch/twiki/bin/view/LHCPhysics/ContributionsYR4

Presently there seems to be no limits on the page numbers (to be clarified by WG1 conveners with SC).

- Signal cross section: WG1 conveners will get back with precise setup for mass scan (wait for final guidelines for SM cross sections for BSM)

- It is possible to use interpolated K-factors (to be used with LO cross section to evaluate NLO cross sections) provided the accuracy of the procedure is carefully assessed

- The impact of MSbar vs on-shell definition of Yuwawa coupling should be assessed

- Additional material on ttH and tH XS is available at

https://twiki.cern.ch/twiki/bin/view/LHCPhysics/CrossSectionYR4

- Regarding the evaluation of the signal ttH cross section one issue is the inclusion of LO+NLO EW corrections, which in total give 0.0 % contribution. One could quote the reference cross section as a NLO QCD+EW result but avoid the inclusion of EW effects in practical computations.

- Additional material on tt+bjets studies involving ATLAS+CMS+Sherpa/OpenLoops+MG5_aMC@NLO at

https://twiki.cern.ch/twiki/bin/view/LHCPhysics/ProposalTtbb