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Analysis status for heavy charged Higgs with H + 

Analysis status for heavy charged Higgs with H + . Higgs WG Meeting CERN, 23 October, 2007. R.Kinnunen, S. Lehti Helsinki Institute of Physic, Helsinki. Contents: - Workplan and status for fully hadronic gg->tbH + , H +  Background analysis for 100 fb -1 with

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Analysis status for heavy charged Higgs with H + 

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  1. Analysis status for heavycharged Higgs with H+ Higgs WG Meeting CERN, 23 October, 2007 R.Kinnunen, S. Lehti Helsinki Institute of Physic, Helsinki R. Kinnunen, S. Lehti

  2. Contents: • - Workplan and status for fully hadronic • gg->tbH+, H+ • Background analysis for 100 fb-1 with • W->mn in tt and W+jet events • Background analysis for 100 fb-1 with • QCD events • ”Hard t reconstruction” in the signal events R. Kinnunen, S. Lehti

  3. Off-line event selection • Veto on isolated electrons and muons, pT >~ 10-20 GeV/c • MET > 100 GeV • t jet reconstruction, ET > 100 GeV • t isolation: no track with pT > 1 GeV/c in the isolation cone of 0.04 < R < 0.4 around the leading track • Electron rejection: At least one HCAL cell with ET > 2 GeV in the t jet • One-prong selection: • – One reconstructed track in the signal cone • – ptrack / Etjet > 0.8 • Three-prong selection: • – Three reconstructed tracks in the signal cone • – Matching between ET(CALO cluster) and S pTtrack to select t -> 3p + n • – S ptrack / Etjet > 0.8 or S ptrack / Etjet < 0.4 • Tagging of one b jet and top mass reconstruction • Transverse mass reconstruction from t jet and MET R. Kinnunen, S. Lehti

  4. Backgrounds for gg->tbH+, H+ Main background processes: tt, W+3jets, QCD multi-jet events In ideal case, - signal at large mT(t jet,MET), with an endpoit at mT(t jet,MET) ~ mH+ - backgrounds from W->tn (tt, W+jets) distributed to mT(t jet,MET) < mW R. Kinnunen, S. Lehti

  5. Sources background in the signal area • Background in the signal area (mT(t jet,MET) > 100 GeV)can be devided • into 3 gategories: • Diffusion of background events to the signal areadue to MET measurement • - This background in tt and W+jets events can be measured with muons • from W->mn decays in tt and W+jets events • - Background due to QCD multi-jet events can be measured in QCD events • measuring fake t probability in other processes • Fake t jets due to difficulty of the t identification • Could be measured from data exploiting g + jet events as proposed in • CMS NOTE-2006/028 • Fake leading tracks (pT > 80 GeV) • Can be reduced with strong quality cuts, studies going on (PFlow group), • L. Wendland for t’s ingg->tbH+, H+ R. Kinnunen, S. Lehti

  6. Background analysis for 100 pb-1 in muon events • Event selection: • Single muon trigger • Off-line selection cuts: • Isolated electron veto to suppress W->en in tt events • One muon with pTm > 100 GeV • Muon isolation • ETmiss > 100 GeV • 3 jets, ET > 20 GeV • W+3jet selection: no b jets, suppression of tt • tt selection: 2 b jets, suppression of W+3jets • mT(m,MET) reconstruction R. Kinnunen, S. Lehti

  7. Background in the signal area can be estimates through: Nttt-sel = (Nttm-sel – NW3jcont) * (et/em) * (eMETt-sel/eMET m sel )* etop rec.t-sel / eb-tag Nw3jt-sel = (Nw3jm-sel – Nttcont) * (et/em) * (eMETt-sel/eMET m-sel)* etop rec.t-sel * eb-tag / (eb-antitag)3 • NW3jconand NW3jconarethe W+3jet and tt contamination to tt and • W+3jet selections • et : to be estimated from MC • not enough events from Z->tt -> m + t jet in this energy scale • - eMET(t sel.): MET efficiency in signal (t jet) selection • - eMET(m sel.): MET efficiency in background (m jet) selection • - eb-tag : to be measured in b enriched tt events • - eb-antitag : can be measured from g+jet events, if fraction of g+b events • is below 1% • top reconstruction: to be checked if affects the shape of the • mT(t jet, ETmiss)distribution R. Kinnunen, S. Lehti

  8. Background analysis for 100 pb-1 in QCD events • Event selection: • Events from tau + MET trigger • At least one jet with pTjet > 100 GeV • One of the jets with pTjet > 100 GeV taken randomly as t candidate • ETmiss > 100 GeV • 3 jets, ET > 20 GeV • one ”b” jet • top mass reconstruction • mT(t candidate,MET) reconstruction Events in the signal area: NQCD(t-sel) = NQCD(QCD-sel) * e(t-miss-id) e(t-miss-id) can be measured in g+jet events R. Kinnunen, S. Lehti

  9. Software version and data samples • - CMSSW version CMSSW_1_6_7 used • Data samples used: • tt: tt0j_mT_70-alpgen, s = 840 pb • W+3 jets:W3jet_0ptw100-alpgen, 0 < pTW < 100 GeV, s = 588 pb • W+4 jets:W4jet_0ptw100-alpgen, 0 < pTW < 100 GeV, s = 124 pb • QCD:QCD_Pt_120_170, 120 < pTjet < 170 GeV • Signal: RelVal160pre8ChargedHiggsTausM200 • mH+ = 200 GeV, 5000 events R. Kinnunen, S. Lehti

  10. Muon off-line selection Muons from reco::MuonCollection - tracker isolation in a cone of DR=0.3 and pTcut = 1 GeV used R. Kinnunen, S. Lehti

  11. MET reconstruction reco::CaloMET used including muons from reco::MuonCollection No MET corrections yet R. Kinnunen, S. Lehti

  12. B tagging JetTagCollection: trackCountingHighPurJetTags 2 tagged b jets, ET(jet) > 20 GeV, discriminator > 1.5 (not optimized yet) R. Kinnunen, S. Lehti

  13. Transverse mass mT(m,MET) distributions Expected behaviour from MC variables in tt events R. Kinnunen, S. Lehti

  14. Transverse mass mT(m,MET) distributions Preliminary results for tt, t1->mnb,t2->hadrons Unnormalized distributions W2->tn and W2->en removed with MC info MET should originate from W->mn tail due to MET resolution Some events from W->mn • Events in the signal area were wound to originate mainly from real neutrinos • from W->tn originating from the secod top • need to implement t-jet veto in the muon selection and second t veto in the • signal selection R. Kinnunen, S. Lehti

  15. Transverse mass mT(m,MET) distributions Preliminary results for W+3jet, W->mn All remaining events at large mT are signal-like with well measured MET Originate from the BW tail of the W need to genetate the W mass in bins to study the effect R. Kinnunen, S. Lehti

  16. First tentative for a ”hard t algorithm” • - Select jets passing the the IsolatedTauTagInfoCollection with • ET > 100 GeV • Parameters for the IsolatedTauTagAlgo: • pTleadingtrack > 20 GeV, R(match) =0.1, R(signal)=0.07, R(isol) = 0.45, • pT(min) = 1 GeV • - Require matching with the MC t jet from gg->tbH+, H+ • - Definition of energy resolution: ETjet / ETvisible MC t -1 • - Event sample used: RelVal160pre9ChargedHiggsTausM200 • - small statistics, 5000 events ! R. Kinnunen, S. Lehti

  17. Visible hadronic t mH+ = 200 GeV h(MC t jet) ET(MC t jet) R. Kinnunen, S. Lehti

  18. Possible algorithm of reconstructing large ET one-prong t’s R. Kinnunen and A. Nikitenko • for good geometrical ECAL-HCAL-track matching do following: • 1. If |ETHCAL+ECAL - pTtrack| < 2 sCALO: use t ~ track p, corresponds to t -> p± + n • If ETHCAL+ECAL – pTtrack > 2 sCALO • 2.1 if |ETHCAL - pTtrack| < 2 sHCAL : uset ~ track p + ECAL cluster, • corresponds to t -> p± + np0 + n with charged pion not interacting in ECAL 2.2 if pTtrack - ETHCAL > 2 sHCAL , p±interaction in ECAL, take the calo jet • 2.3 if ETHCAL - pTtrack > 2 sHCAL, hadronic jet, reject 2.1) 2.2) - Optimization of the cones for energy collection in ECAL and HCAL needed HCAL ECAL p0 p0 p± p± R. Kinnunen, S. Lehti

  19. Test CALO cluster/track matching for one-prong t’s Definition: ETcalo cluster / pTtrack – 1 Calo cluster reconstruction from CaloRecHits with DR(ECAL impact point, cell) < 0.1 in ECAL DR(ECAL impact point, cell) < 0.2 in HCAL One prong decay mode without neutrals,t -> h±n Matching variable Almost all events within |ETcalo cluster / pTtrack – 1| < 0.5 R. Kinnunen, S. Lehti

  20. Calo cluster/track matching for t -> p+ +n p0 + n Test here the HCAL cluster/track matching III II I III Bad track ? reject pt jet ~ ptrack Matching variables R. Kinnunen, S. Lehti

  21. t candidates with Calo Cluster/track matching, region II Energy resolution for t -> p+ +n p0 + n Loss of energy observed, try to minimize the effect with an asymmetric cut: - 0.5 < ETcalo cluster / pTtrack – 1 < 0.2 Resolutions Energy resolution for t -> p+ + n with Calo Cluster/track matching R. Kinnunen, S. Lehti

  22. HCAL cluster/track matching for t -> p+ +n p0 + n, Region III Matching variables Hadronic jet: reject HCAL cluster/track matching: add the ECAL cluster to include p0’s p±interaction in ECAL, take the calo jet Select large window |ETHCAL cluster / pTtrack – 1 |< 0.8 due to energy loss in this area R. Kinnunen, S. Lehti

  23. Comparison with reco::Jet Resolutions R. Kinnunen, S. Lehti

  24. All one-prong t’s selected with MC info R. Kinnunen, S. Lehti

  25. Conclusions and plans • Background analysis with W->mn in tt and W+3jet events and in QCD events in progress Large mass tail observed in mT(m,MET): - mainly due to W->tn in tt events - due to natural W width in W+3jet events • First results from a ”hard -tau” algorithm for one-prong t’s in gg->tbH+, H+ with ETt-jet > 100 GeV were presented - Improvement of t jet resolution possible with a simple algorithm • New group members: Katri Lassila, fake t probability from g+jet events Matti Kortelainen, top mass reconstruction, Benedict Hegner should join later Richard Cavanaugh, t with PFlow, MET R. Kinnunen, S. Lehti

  26. Backup slides R. Kinnunen, S. Lehti

  27. 4. EBRecHit const CaloJet* caloJet = dynamic_cast<const CaloJet*>(&(iTau->jet())); vector<CaloTowerRef> towers = caloJet->getConstituents(); for(vector<CaloTowerRef>::const_iterator iTower = towers.begin(); iTower != towers.end(); iTower++){ // access CaloRecHits for(size_t j = 0; j < numRecHits; j++) { DetId recHitDetID = (**iTower).constituent(j); DetId::Detector detNum=recHitDetID.det(); if( recHitDetID.det() == DetId::Ecal ){ if( recHitDetID.subdetId() == 1 ){ // Ecal Barrel EBDetId ecalID = recHitDetID; EBRecHitCollection::const_iterator theRecHit = EBRecHits->find(ecalID); if(theRecHit != EBRecHits->end()){ DetId id = theRecHit->detid(); const CaloCellGeometry* this_cell = EB->getGeometry(id); if(this_cell){ GlobalPoint hitPos = this_cell->getPosition(); double eta = hitPos.eta(); double phi = hitPos.phi(); double theta = hitPos.theta(); if(theta > 3.14159) theta = 2*3.14159 - theta; // ecalCells.push_back(hitPos); double energy = theRecHit->energy(); double et = energy * sin(theta); Double_t px = energy * sin(theta)*cos(phi); Double_t py = energy * sin(theta)*sin(phi); Double_t pz = energy * cos(theta); R. Kinnunen, S. Lehti

  28. 5. ECAL impact point - using TransientTrack const TransientTrack transientTk = (transientTrackBuilder->build(&(leadTk))); - ecalHitPosition is taken as maxTowerEt position TrajectoryStateClosestToPoint TSCP = transientTk.trajectoryStateClosestToPoint(ecalHitPosition); GlobalPoint trackEcalHitPoint = TSCP.position(); R. Kinnunen, S. Lehti

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