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Review of Charged Higgs Trigger strategies

Review of Charged Higgs Trigger strategies. Simone Gennai Centro Studi Enrico Fermi, Roma. Trigger: the first step towards an analysis. Problem to face: reduce a huge amount of non interesting events and do it in a short time !. At Tevatron: - s Inel ~ 50mb - s top ~ 7pb

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Review of Charged Higgs Trigger strategies

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  1. Review of Charged Higgs Trigger strategies Simone Gennai Centro Studi Enrico Fermi, Roma

  2. Trigger: the first step towards an analysis Problem to face: reduce a huge amount of non interesting events and do it in a short time ! At Tevatron: -sInel ~ 50mb -stop ~ 7pb -About a factor 1/1010 Trigger rejects 99.995% of the crossings. At LHC the situation is similar and also the trigger systems are “similar” Simone Gennai, Centro Studi Enrico Fermi - Roma

  3. Charged Higgs @ Tevatron Production: • Major decay modes: • H+->t+n • Most important • H+->cs • H+->t*b->W+bb • H+->W+h->W+bb • BR’s depend on: • tan b, m(H+) • Differ from W+ BR’s t ->bH+ (mH < mt-mb) Simone Gennai, Centro Studi Enrico Fermi - Roma

  4. Analysis strategies • Find some inconsistencies with the top decay branching ratios given from the Standard Model • As the BR(H+->tn) > BR(W->tn), the total number of leptons in the final state is different if the diagram with the charged Higgs is present • The analysis follows the top precision measurements Simone Gennai, Centro Studi Enrico Fermi - Roma

  5. CDF Detector Simone Gennai, Centro Studi Enrico Fermi - Roma

  6. CDF Trigger system 3 Levels Trigger: L1 output rate = 20kHz -Hardware (5 msec) L2 output rate = 350 Hz -Hardware and Software (30 msec) L3 output rate = 75 Hz -Completely Software Simone Gennai, Centro Studi Enrico Fermi - Roma

  7. CDF Charged Higgs Trigger strategies are the same as the one used in the top measurements: High PT Lepton Some samples used Jet triggers or relaxed cuts lepton trigger for efficiency studies. Look at four tt final states: • di-lepton + jets • lepton + jets (=1 b-tag) • lepton + jets (≥ 2 b-tags) • lepton + tau + jets Simone Gennai, Centro Studi Enrico Fermi - Roma

  8. High Pt Electron Trigger • |hdet |<1.0 • Level 1 • Calo Tower energies are summed to form trigger towers • At least one tower must have: • ET > 8 GeV • Ehad/Eem < 0.125 • At least one COT (XFT) track with pT > 8 GeV pointing at tower • Level 2 • Clustering algorithm combines tower energies to form a cluster • Cluster must have: • XFT track with pT > 8 GeV matched to seed tower of cluster • ET > 16 GeV • Ehad/Eem < 0.125 Simone Gennai, Centro Studi Enrico Fermi - Roma

  9. High Pt Electron Trigger • Level 3 • EM cluster reconstructed by offline algorithm must have: • ET > 16 GeV • Ehad/Eem < 0.125 • 3D COT track with pT > 9 GeV pointing at the cluster • Typical Rates • For L=2.5x1031 cms-2s-1: • L1 accepts 25 Hz • L2 accepts 3 Hz • L3 accepts 1 Hz Simone Gennai, Centro Studi Enrico Fermi - Roma

  10. D0 analysis: fully hadronic final state • It considers the following cases: • Both top quarks decay into H±(->tn) • Two tau jets are present in the final state • One top quark decay into H± and the other into W • Only W hadronic decays are considered • 1 tau jets and light quark jets are present in the final state Simone Gennai, Centro Studi Enrico Fermi - Roma

  11. D0 analysis: Jet trigger • Level 1 • 4 trigger towers ET > 5.7 GeV • 3 large tiles ET > 15 GeV • Cumulative efficiency: 98 % (on top events) • Level 2 • 5 jets R = 0.3 • |h| < 2.5 • ET > 10 GeV, HT > 120 GeV • Cumulative efficiency: 92 % • Level 3 • HT > 115 GeV from R = 0.5 jet cones • |h| < 2.5 • ET > 8 GeV • Cuts for spurious jets • Cumulative efficiency: 87 % Simone Gennai, Centro Studi Enrico Fermi - Roma

  12. LHC analysis • Most important production channels • gb->tH- (for mH > mtop) ,t->bH- (for mH < mtop, in top pair production) • Lepton from W decay can be used to trigger on. • Two possible decay mode for the charged Higgs: • H-->t n-> hadrons + n • (Relevant in the complete mass range for high tanb) • A dedicated Tau Trigger has been developed for the fully hadronic final state • H-->tb -> qq’ + b + b • (Relevant for mH- >mtop ) Simone Gennai, Centro Studi Enrico Fermi - Roma

  13. Schematic view of the CMS detector Simone Gennai, Centro Studi Enrico Fermi - Roma

  14. ATLAS and CMS Trigger System Multi Level Trigger System Trigger after Level 1 must have rejection power ~1000. “Triggerable” objects are: Electrons/gammas, muons, jets, Tau jets (hadronic tau decay), missing transverse energy, etc. etc. Combined trigger (e or m + t) are also forseen. Simone Gennai, Centro Studi Enrico Fermi - Roma

  15. H+->tb -> Wbb->qq’bb The top quark produced in association with the charged Higgs provides the lepton for the trigger. electron trigger Selections are based on pT cut and isolation criteria. Total L1 Rate ~ 5kHz Muon isolation Simone Gennai, Centro Studi Enrico Fermi - Roma

  16. -Region of Interest (,, pT and energy sum of candidate object) -Coarse granularity info from calorimeter Event Display HZZ 2e2 L1 calo L2 calo • Seeded by L1 RoI • Full granularity • Calo (shower shape) and tracking L2 tracking Electron Trigger Selection -Seeded by L2 or full event access -refined alignment and calibration data -Calorimeter and tracking - offline-like algorithms EF calo EF tracking Simone Gennai, Centro Studi Enrico Fermi - Roma

  17. e25i for ET>22 GeV 50% of the clusters come from real electrons Efficiency has flat distribution for high ET Electron/Photon Trigger Trigger Selection is performed on an event basis and includes the double and single object trigger items for electrons and photons. TriggerEfficiency Rate e25i 76.2 % 46 4 Hz (low) TriggerEfficiency Rate 2e15i 60 % few Hz Simone Gennai, Centro Studi Enrico Fermi - Roma

  18. CMS Muon L1 Trigger Simone Gennai, Centro Studi Enrico Fermi - Roma

  19. Gg->tbH+->qq’ bb tjetn Single Tau trigger has been developed for this fully hadronic final state. Usefulfor high values of the Higgs boson mass See Casado’s talk for more details Simone Gennai, Centro Studi Enrico Fermi - Roma

  20. LEP: Production mechanimsLow mass Higgs boson Trigger requirement are very loose Simone Gennai, Centro Studi Enrico Fermi - Roma

  21. Delphi Trigger system (LEP I) • T1 & T2 (hardwired decision, fully syncronous with the Beam Cross Over • T1: 90kHz -> 800 Hz (11 msec) • T2: 800 Hz -> 4 Hz • T3 & T4 Software driven trigger • T3: 4 Hz -> 2 Hz • T4: reduces further with quality constraint Simone Gennai, Centro Studi Enrico Fermi - Roma

  22. Doubly-charged Higgs (H±±) • Short lived particle: • Most of the analysis are focused on ee, mm decays (also em, et at HERA) • Single or double lepton trigger is used • Long lived particle: • It seems like an heavy muon • Inclusive muon trigger is used Simone Gennai, Centro Studi Enrico Fermi - Roma

  23. Conclusions • The Trigger is the first step of the analysis • At the hadron collider it is foundamental for new physics discovery • Most of the trigger strategies share the same logic • In the future triggers on hadronic tau decays will be have a keyrole in several analysis Simone Gennai, Centro Studi Enrico Fermi - Roma

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