H->bbbar Final State Subgroup (LHC HXS WG)

Contribute to Sharepoint discussions here: VH production, ttH production, bb final state.

Group Contacts and Contributors

• ATLAC/CMS/LHCb Contacts: Chris Potter (Oregon)/Jim Olsen (Princeton)/Clara Matteuzzi (Milano-Bicocca)
• Experiment: Chris Potter, Jim Olsen, Clara Matteuzzi, Chris Neu, Chris Collins-Tooth, Giacinto Piaquadio, Douglas Wright, Michiel Sanders, Ben Smart, Andrea Messina
• Theory: Laura Reina, Michael Spira

All contributors are welcome!

Meeting Agendae

• February 2011
• March 2011
• May 2011

Plan of Activity

• VH->Vbb differential K-factor (LO to NLO) in signal and background after common cuts with MC@NLO and POWHEG
• ttH->ttbb differential K-factor (LO to NLO) in signal with aMC@NLO
• evaluation of VH->Vbb and ttH->ttbb cross section uncertainties at NLO after common cuts

Common cuts definition between CMS/ATLAS/LHCb

VH->Vbb for LHCb

Boosted VH->Vbb

• pt(H)>200 GeV
• pt(V)>200 GeV
• No additional C/A jets with pt > 20 GeV (|eta|<2.4)

Non-boosted VH->Vbb (PRELIMINARY proposal from ATLAS)

• pT(e/mu) > 20-25GeV
• |eta(e/mu)| < 2.5
• 2 jets with pT>25GeV
• MET > 25GeV (????)

Non-boosted ttH->ttbb

• exactly one isolated lepton with pt>25 GeV (20 GeV) e(mu).
• >=6 jets with pt>20 GeV
• >=4 b-tagged jets with pt>20 GeV

Boosted ttH->ttbb

• pT(H)>2*mH

Baseline Common Parameters

Use the parameters from this TWiki. These will be updated with PDG2010 (they are now PDG2009). For PDFs, use the NLO PDFs recommended by PDF4LHC: CTEQ6.6, MSTW2008nlo, NNPDF2.0.

Available Tools

• MC@NLO
• POWHEG Box
  • W+bb in POWHEG
• aMC@NLO
  • ttH in aMC@NLO (contact the authors at amcatnlo@cernNOSPAMPLEASE.ch).

Results

References

• ATLAS Sensitivity to the Standard Model Higgs in the HW and HZ Channels at High Transverse Momenta ATL-PHYS-PUB-2009-088
• Search for ttH->ttbb CERN-OPEN-2008-020 (pp. 1333-1363)
• Search for H->bb in Association with a ttbar Pair at CMS CMS-NOTE-2006-119
• PDF4LHC Working Group Interim Recommendations arXiv:1101.0538
• Handbook of LHC Higgs Cross Sections: 1. Inclusive Observables CERN-2011-002

-- ReiTanaka - 02-Oct-2010