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14-04-201114-04-2011 HEP HEP ConferenceConference 11
NMSSM Higgs SearchNMSSM Higgs Search
0 0 0
1 1 1h 4 2 2 jets
Search for neutral NMSSM Higgs
Studies at 10 TeV, and with the 2010 data @ 7 TeV
Jehad MousaUniversity of Cyprus
ANNUAL MEETING OF THE HELLENIC SOCIETY FOR THE STUDY OF HIGH ENERGY PHYSICS
April 14-16, 2011, University of Patras, Greece
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NNMSSMMSSM
The Next-to-Minimal Supersymmetric Standard Model (NMSSM) extends the MSSM by the introduction of a singlet superfield ( )
The NMSSM naturally solves the μ-problem of the MSSM.
The Higgs sector of the NMSSM contains (three CP-even bosons h1, h2, h3 and two CP-odd higgs bosons α1, α2) and two charged higgs bosons (h ).
S
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The benchmark pointsThe benchmark points
• The lightest pseudoscalar higgs boson is rather light,
and the lightest CP-even higgs has enough phase space for the decay into two pseudoscalar higgs boson , to be kinematically accessible.
• The BR for the decay is very large and this new channel is the dominant one.
• Concerning the further decay of the lightest pseudoscalars, there are two possibilities: – Either and the boson decays into a pair of b quarks
or a pair of tau leptons, leading to and final states, – or and the dominant decay mode of the boson is into
a pair of tau leptons, leading to final state.
01
40 50M GeV
01a
M
0 0 01 1 1h
0 0 01 1 1h
01
10M GeV
01
0 0 01 1 1 4 ,4h b 2 2b
01
10M GeV
01
0 0 01 1 1 4h
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Channels investigated and Channels investigated and associated backgroundassociated background
The signal process:
A Vector Boson Fusion: Two different types of scenarios are considered, depending on
Scenarios with are disfavored when LEP data for Z2b and Z4b final states are taken into account.
On the contrary, scenarios with are favored by the same data and can even account for 2σ excess observed in the Z2b final state in the vicinity.
0 01 1
2 ( 4.2 ) 2 .b b ba am m m GeV orm m
01
2 bam m
01
2 bam m
01
2 bam m
01
100h
M GeV0 0 01 1 1h a a 4 2 2 jets
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Channels investigated and Channels investigated and associated backgroundassociated background
higgs-strahlung: 0 0 01 1 1
ll
l
l ,bb,bbWh l a a
l ,bb,
0 0 01 1 1
l l ,bb,bbZh l l a a
l l ,bb,
0 0 01 1 1h a a 0
1h The decay, with produced in higgs-strahlung with leptonic decays of the W or Z boson, which can give a very clean and almost background free signal, is one of the most promising higgs decay channels according to the last investigation of phenomenological scenarios
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Channels investigated and Channels investigated and associated backgroundassociated background
* *Z / and W
Background processes: ZZjj and WZjj production:
TTbar production: t Wb
Zbbbar and Wbbbar production:
* *Z / and W
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Cross Section @ 10 TeVCross Section @ 10 TeV
• Vector Boson Fusion
Mh (GeV) Typical cross –section for VBF (fb)
LO NLO105 32.68 31.69 115 29.81 28.93125 27.16 26.39135 24.95 24.29145 23.19 22.52
0 0 01 1 1h a a 4 2 2hadronic 6
For L = 200 pb-1, NLO = 6.5 and NNLO = 6.3
2 2 2( ) ( )* ( )* ( ) * ( ) * ( )qqh BR h aa BR a BR BR had
M. Spirq, Fortsch Phys. 46 (1998) 203, http://people.web.psi.ch/spira/proglist.html
92.6% 17.8% 65.4%93.8%
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Cross SectionCross Section
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μ-τ μ-τ SkimSkim
Muon• Global Muons, Pt > 6 GeV, abs(η) <2.5Tau• caloRecoTauDiscrimainationByLeadingTrackPtCut: 0.5
• Calo Tau: Leading Track Pt > 5GeV within ΔRmatching = 0.1 Muon-Tau• DiTauAntiOverlapSelector ΔR = 0.01
Sample Gen Events
σ (fb) MC Filter Efficiency
Skim Efficiency
884000 32.68 1 0.87740
ZZ 4l 902140 189.86 0.3165 0.74316
Zbb 4l 1063204 56200 0.007 0.74925
1011062 290900 0.00317 0.86100
0 01 1
0 0 01 1 1 4
5.3 , 105a h
h a aM GeV and M GeV
tt
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Event SelectionEvent Selection
Vertex Selection p(chi2Vertex) > 0.01 -25 < zVertex < +25 cm
Muon Selection global Muon -2.1 < eta(Muon) < +2.1 Pt(Muon) > 8 GeV Muon Track iso. Muon ECAL iso. Muon pi-Veto Muon Track IP
Tau Selection
Tau not overlapping w. Muon
-2.1 < eta(Tau) < +2.1 Pt(Tau) > 10 GeV Tau lead. Track find. Tau lead. Track Pt Tau 1||3-Prong Charge(Tau) = +/-1 Tau mu-Veto Tau Electron-Veto
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Event Selection Event Selection
Muon-Tau Selection
Charge(Muon+Tau) = 0
Acoplanarity(Muon+Tau)
MT (Muon-MET) < 50 GeV
dR(Muon-Tau) < 0.5
a-a Selection
dR(a-a) > 0.3
Acoplanarity (a+a)
MT (a-MET) < 50 GeV
MC
processed
LwN
Normalized
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CutsCuts
5.0315.0315.0295.0294.7374.4443.8153.8153.8133.7123.3333.2603.1943.191
131.997131.997131.989131.989130.895128.882126.768126.768126.766126.483110.132106.785104.809102.897
6.6376.6376.6336.6336.6176.5036.4546.4466.4205.2125.1925.1885.1645.164
Cut
Htoaa
TTbarFourl
ZZFourl
llbb
gen. Phase-Space Vertex p(chi2Vertex) > 0.01 -25 < zVertex < +25 cm global Muon -2.1 < eta(Muon) < +2.1 Pt(Muon) > 8 GeV Tau not overlapping w. Muon -2.1 < eta(Tau) < +2.1 Pt(Tau) > 10 GeV Muon Track iso. Muon ECAL iso. Muon pi-Veto Muon Track IP
44.12944.12944.11844.11843.86242.78542.12542.12442.09138.38135.58034.98634.56134.026
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. * visp p 1 5 20
Tau lead. Track find. Tau lead. Track Pt Tau 1||3-Prong Charge(Tau) = +/-1 Tau mu-Veto Tau Electron-Veto dR(Muon-Tau) < 0.5 Charge(Muon+Tau) = 0 Acoplanarity(Muon+Tau) M_{T}(Muon-MET) < 50 GeV dR(a-a) > 0.3 Acoplanarity(a+a) M_{T}(Muon-MET) < 50 GeV
3.0612.9751.7261.7041.4841.4030.244
0.224
0.224
0.216
0.145
0.002
0.002
0.002
101.655100.23478.14476.60771.21047.4935.5723.2703.2702.0621.1740.002
0.002
0.002
Cuts
4.2384.1233.7373.7253.5030.723
0.013
0.007
0.007
0.006
0.003
0.000
0.000
0.000
27.84525.81017.51717.12214.5326.2611.0140.613 0.613 0.582 0.410 0.000 0.000 0.000
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Muon Identification Muon Identification
Muon Reconstruction
( ) ( )( )
T T
T
p RECO p MCp MC
Muons: “global muons”
PT Resolution
/
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Tau Identification Tau Identification
Tau Reconstruction
( ) ( )( )
T T
T
p RECO p MCp MC
Taus: particle-flow techniques “PFTau”
PT Resolution
/
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Missing Transverse Energy (MET)Missing Transverse Energy (MET)
The pfMET algorithm
PMET Resolution MET Resolution
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Total number of Taus and muonsTotal number of Taus and muons
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Mass ReconstructionMass Reconstruction
PTmiss
vμ
μ
a1 τ vτ
μhad
vμ
a1
h1
τ
vτ
had The mass and PT of the h are sufficiently large to give a considerable boost to its decay products. The directionof the a1, of the two τ, of the two μ, of the two hadron and of the three neutrinos are then nearly parallel. The missing transverse momentum originates exclusively from the neutrinos from the decay chain of the h. The masses of the final state leptons and the a1 are neglected compared to the typical mass of h1.
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Collinear ApproximationCollinear Approximation
1 2 1 2, , , ,
2 1 2 1 2, , , , , ,( ) ( )
x h y h y h x hmiss miss
x h y h y h y h x h x h
p p p px
p p E p p E
1 2 1 2, , , ,
1 2 1 2 1, , , , , ,( ) ( )
x h y h y h x hmiss miss
y h x h x h x h y h y h
p p p px
p p E p p E
1 2
1 21 2h h
a a
E Ex , x
E E
1 2, ,1 2 1 2
, , , , ,1 2
T h T hT a T a T h T h T miss
p pp p p p E
x x
2 21 2 1 2
2 2 21 2 2
1 2
( )
2
a a a a
h h h ha
m p p
m m mm
x x
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xx1 1 andand xx2 2 before before Muon-Tau SelectionMuon-Tau Selection
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ΔΔR and mass distributions between R and mass distributions between muon-muon-jetjet
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ΔΔR and mass distributions between a-aR and mass distributions between a-a
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Invariant mass of a and h using Invariant mass of a and h using Collinear Approximation Collinear Approximation
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Data and Monte Carlo Samples at 7 Data and Monte Carlo Samples at 7 TeVTeV
Data Run-range/Mu/Run2010A-Nov4ReReco_v1/RECO 136033-144114/Mu/Run2010B-Nov4ReReco_v1/RECO 146428-149442Trigger PathHLT_Mu9, HLT_IsoMu9, HLT_Mu11, HLT_Mu15, HLT_IsoMu13HLT_IsoMu9_PFTau15, HLT_IsoMu11_PFTau15
Sample Gen Events
σ (fb)(NLO)
MC Filter Efficiency
Skim Efficiency
693000 14.44 1 0.73440 01 1
0 0 01 1 1 4
9 , 120a h
h a aM GeV and M GeV
Monte Carlo
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Cut Data Htoaagen. Phase-Space 5091469.0000 0.5220Muon Trigger 2274012.0000 0.3556Data quality 2274012.0000 0.3556Vertex 2274012.0000 0.3556Vertex quality 2274012.0000 0.3556-24 < zVertex < +24 cm 2274012.0000 0.3556global Muon 2274012.0000 0.3552-2.1 < eta(Muon) < +2.1 2214682.0000 0.3551Pt(Muon) > 9 GeV 2152200.0000 0.3538Tau not overlapping w. Muon 2150401.0000 0.3537-2.3 < eta(Tau) < +2.3 2148890.0000 0.3537Pt(Tau) > 10 GeV 1839265.0000 0.3439Muon VBTF id. 1627993.0000 0.3391Muon iso. 545575.0000 0.3385Muon Track IP 545575.0000 0.3385Tau lead. Track find. 545575.0000 0.3385Tau lead. Track Pt 538077.0000 0.3314Tau 1||3-Prong 538077.0000 0.3314Charge(Tau) = +/-1 538077.0000 0.3314Tau mu-Veto 198173.0000 0.3176Tau e-Veto 196006.0000 0.3169dR(Muon-Tau) < 0.5 3662.0000 0.0549M_{T}(Muon-MET) < 40 GeV 3473.0000 0.0463P_{#zeta} - 1.5*P_{#zeta}^{vis} > -20 GeV 2724.0000 0.0401not Charge(isoMuon+isoMuon) = 0 2722.0000 0.0383dR(a-a) > 0.3 45.0000 0.0192Acoplanarity(a+a) 43.0000 0.0164M_{T}(aa-MET) < 50 GeV 43.0000 0.0095no E_{T} > 20 GeV central Jet with b-Tag 41.0000 0.0095Charge(Muon+Tau) = 0 27.0000 0.0095charge = 0 16.0000 0.0041
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Efficiency SelectionEfficiency Selection
Cut Data_MuTau Htoaa------------------------------------------------------------------------------------------------gen. Phase-Space 1.0000 1.0000Muon Trigger 0.4466 0.6813Data quality 0.4466 0.6813Vertex 0.4466 0.6813Vertex quality 0.4466 0.6813-24 < zVertex < +24 cm 0.4466 0.6813global Muon 0.4466 0.6804-2.1 < eta(Muon) < +2.1 0.4350 0.6803Pt(Muon) > 9 GeV 0.4227 0.6777Tau not overlapping w. Muon 0.4224 0.6776-2.3 < eta(Tau) < +2.3 0.4221 0.6775Pt(Tau) > 10 GeV 0.3612 0.6588Muon VBTF id. 0.3197 0.6496Muon iso. 0.1072 0.6484Muon Track IP 0.1072 0.6484Tau lead. Track find. 0.1072 0.6484Tau lead. Track Pt 0.1057 0.6349Tau 1||3-Prong 0.1057 0.6349Charge(Tau) = +/-1 0.1057 0.6349Tau mu-Veto 0.0389 0.6084Tau e-Veto 0.0385 0.6070dR(Muon-Tau) < 0.5 0.0007 0.1051M_{T}(Muon-MET) < 40 GeV 0.0007 0.0886P_{#zeta} - 1.5*P_{#zeta}^{vis} > -20 GeV 0.0005 0.0768not Charge(isoMuon+isoMuon) = 0 0.0005 0.0734dR(a-a) > 0.3 0.0000 0.0368Acoplanarity(a+a) 0.0000 0.0314M_{T}(aa-MET) < 50 GeV 0.0000 0.0183no E_{T} > 20 GeV central Jet with b-Tag 0.0000 0.0182Charge(Muon+Tau) = 0 0.0000 0.0182charge = 0 0.0000 0.0079
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mass distributions mass distributions
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ΔΔR and mass distributions between R and mass distributions between muon-muon-jetjet
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ΔΔR and mass distributions between a-aR and mass distributions between a-a
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ConclusionConclusion
Results of a search for NMSSM neutral Higgs to four taus productions in the channel 2mu + 2tau have been presented.
No evidence fo a NMSSM neutral Higgs signal in the proton-proton collision data collected by the CMS experiment in 2010 is found.
7s TeV
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ThanksThanks
We acknowledge support from Research Promotion Foundation (IPE) cyprus