ttH(120), H bb
description
Transcript of ttH(120), H bb
CMS HCAL/JetMET @ CERN, 15-June-2001 S.Kunori 1
ttH(120), H ttH(120), H bb bbttH(120), H ttH(120), H bb bb
U. of Maryland
Shuichi Kunori
15-June-2001
CMS Note 2001/xxx
D.Green, K.Maeshima, R.Vidal, W.Wu, S.Kunori
CMS HCAL/JetMET @ CERN, 15-June-2001 S.Kunori 2
SM HiggsSM HiggsSM HiggsSM Higgs
gg fusion WW/ZZ fusion
associatedHtt
associated WH, ZH
production decay
CMS HCAL/JetMET @ CERN, 15-June-2001 S.Kunori 3
1 iso. lepton (PT>10GeV) 6 jets (4 b tag) (ET>20GeV) -> max. likelihood (b likeliness, W mass, top mass …)
MH=115 GeV
Bg: ttbb, ttjj, ttZ0
Mass(jj)
MH
5
30fb-1
mistagging probability (%)
m/m=3.8% (stat)
bb
(V.Drollinger)
CMS HCAL/JetMET @ CERN, 15-June-2001 S.Kunori 4
1 iso. lepton (e,) (PT>20GeV)
only 2 jets (b-tag) (ET>30GeV)MT(W) -> events in higgs mass window
MH=115 GeV
Bg: Wjj, tt, tb
5
300fb-1
bb
CMS HCAL/JetMET @ CERN, 15-June-2001 S.Kunori 5
CouplingsCouplingsCouplingsCouplings
CMS HCAL/JetMET @ CERN, 15-June-2001 S.Kunori 6
ttHttHttHttH
Final state:
t Wb lbt Wb jjbH bb
1 isolated leptonMET6 jets (ET>20GeV) - 4 b-tags
CompHEP V41.10CMGEN CompHEP-PYTHIA interface V46 PYTHIA 6.157 b-tag simulator for pre-selectionCMSIM 120Analysis cone jet finder
CMS HCAL/JetMET @ CERN, 15-June-2001 S.Kunori 7
# of Jets (E# of Jets (ETT>20GeV)>20GeV)# of Jets (E# of Jets (ETT>20GeV)>20GeV)
ttH ttHw/o em cluster
ttbb ttbbw/o em cluster
Minimum 5 jets4 b-tagged
CMS HCAL/JetMET @ CERN, 15-June-2001 S.Kunori 8
Leading Jets & leptonLeading Jets & leptonLeading Jets & leptonLeading Jets & lepton
ttH
ttbb
ttZ
L1 Trigger:
1 lepton + ET(jet)>100GeV
HLT
b-tag
100GeV
0 200 400 GeV
Offline:
only one loosely isolated lepton, i.e.
(ETcone-ET
lep)/ETcone<0.5
PT>20GeV in ||<2.5
CMS HCAL/JetMET @ CERN, 15-June-2001 S.Kunori 9
Mass in ttH sampleMass in ttH sampleMass in ttH sampleMass in ttH sample
qq(W)
qqb(top)
lb(W)
bb(H)
CMS HCAL/JetMET @ CERN, 15-June-2001 S.Kunori 10
Kinematics VariablesKinematics VariablesttH (solid) ttbb (dash)ttH (solid) ttbb (dash)Kinematics VariablesKinematics Variables
ttH (solid) ttbb (dash)ttH (solid) ttbb (dash)
M(tbb) (t-bb)
y(t-bb)
R(t-bb)
Ry(t-bb)
*(b-bb)At bb rest system
CMS HCAL/JetMET @ CERN, 15-June-2001 S.Kunori 11
y distributiony distributionttH(solid), ttbb(dash), ttZ(dot)ttH(solid), ttbb(dash), ttZ(dot)
y distributiony distributionttH(solid), ttbb(dash), ttZ(dot)ttH(solid), ttbb(dash), ttZ(dot)
|y| < 1
CMS HCAL/JetMET @ CERN, 15-June-2001 S.Kunori 12
Mass(bb)Mass(bb)for ttH + ttbb + ttZfor ttH + ttbb + ttZ
Mass(bb)Mass(bb)for ttH + ttbb + ttZfor ttH + ttbb + ttZ
Particle level
CMSIM
|y|<1.0
|y|<1.0
No y cut
No y cut
S/B 1/2 ~11.8
(S/B ~1/1)
Need good b-tagging !