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Search for New Vector Boson from Minimal Higgless Model at CMS

Explore the discovery potential of a new charged boson predicted by the Minimal Higgless model at CMS using upgraded CMSSW software. Analyzing signal samples, backgrounds, event selection, and systematic uncertainties to advance research.

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Search for New Vector Boson from Minimal Higgless Model at CMS

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  1. Search for New Vector Boson from Minimal Higgless Model at CMS(upgraded,based on CMSSW_1_8_4 FastSimulation) Bian J. G. Chen G. M. CMS group Institute of High Energy Physics Wang J.X. Theory division Institute of High Energy Physics Qi Wei Zhang B. He H.J. Kuang Y.P. Qinghua University China, 2008 Aug 23

  2. Ungraded ingredients 1. CMSSW_1_6_9 is replaced with CMSSW_1_8_4 so that trigger simulation is available 2. Optimization of Some of selection criteria 3. 10 % uncertainty of luminosity is replaced with 5%. 4. Uncertainty of bacground cross section is taken into accout.

  3. outline Introdution Signal sample Backgrounds Event selection Systematic uncertainties Summary

  4. Introduction Motivation : this work demonstrates the CMS discovery potential of new charged boson predicted by the Minimal Higgsless model in the process . We give integrated luninosity required to discovery 5sigma signal as a function of mass.

  5. Introduction(con’t) If Higgs do not exist, the unitarity violation will apear in the scattering ofmassive gaugeW±Z0→ W±Z0. To postpone unitarity, Higgsless models are proposed—new weakly coupled particles appear at the TeV scale. The typical ones are : 5d Higgsless models —tower of KK gauge states

  6. Minimal Higgsless model Hep-ph/0708.2588predicts • Just one pair of new bosons as light as 400 GeV, in additon to SM weak boson and a vector- like heavy fermion. • do not decay to lepton pairs • Widths are narrow for 0.4 and 0.5 GeV mass Introduction(con’t)

  7. Introduction(con’t) Feynman Digram pp→W1qq’ →W±Z0qq’ Invariant mass distribution of W±Z0 for MW1=500GeV

  8. Signal sample The generator authors are ones of Hep-ph/0708.2588 The process is fraction(sub 1)/fraction(sub 2) ≈2 The element matrix is calculated at tree level based on Minimal Higgsless Model.

  9. Signal sample(con’t) the generator is interfaced with PYTHIA for the initial and final state radiation and parton hadronization. Then interfaced with CMSSW_1_8_4* for FastSimulation. The default pileup and 1033 trigger are taken into account. Parton Distribution Functions is cteq6l * last version: CMSSW1_6_9

  10. Signal sample(con’t) Cross sections and Events for and Luminosity = 50/fb Mass units: GeV, CS units: fb, Norm=CS*LU/EVTS

  11. Signal sample(con’t) Cross sections and Events(con’t) for and Luminosity = 50/fb Mass units: GeV, CS units: fb, Norm=CS*LU/EVTS

  12. background samples The generator is PYTHIA. The simulation is CMSSW_1_6_9 Fast Simulation. It has pileup, not trigger. pp→WZ0→3μν (isub=23) cross section is 97.33 fb, irreducible pp→WZ0qq’→3μνqq’ (isub=73) cross section is 6.21E-2 fb, irreducible pp→WW→2μ2ν(isub=25) cross section is 8.21E+2 fb,plus a fake μ

  13. background samples(con’t) pp→ WWqq’ →2μ2νqq’ (isub=72,77) cross section=1.42E+3 fb, plus a fake μ pp→Z0 Z0→4μ(isub=22) cross section=17.57fb, fourthμlost pp→Z0 Z0qq’→4μqq’ (isub=71,76) cross section=5.48E-3fb, fourthμlost pp→ttbar→W+W-qq’→2μqq’ (isub=81,82) cross section=5.73E+03 fb pp→Zbb→2μbb(isub=1,30) cross section=1.54E+05 fb, thirdμfrom b

  14. background samples(con’t) Cross sections and Events set luminosity =50/fb

  15. Trigger Signal evevnts are produced with CMSSW_1_8_4 FastSimulation, in which HLT trigger simulation is availablefor 2×1033 lumonosity: double muon pt >7 GeV and |η|<2.5, M2muon>70 GeV, i.e. HLT2MounZ tigger. Trigger efficiency: Background events are produced with CMSSW_1_6_9, no trigger is available for background events, but it can be neglected safely,because number of background events is 2.6 (all page is upgraded ingredient)

  16. Events selection Set W1 mass to be 700 GeV for instance Cut 1: Number of muons is required to be 3, including , Eachμis ParamGlobalMuons, and satisfies and within ∆R=sqrt(∆ η2+ ∆φ2) <0.3, Super Cluster energy <5 GeV.

  17. Events selection(con’t) Cut 2: number of Jets≥1,Each Jet is iterativeCone5CaloJets, satisfies

  18. Events selection(con’t) Cut 2: number of Jets≥1(con’t)

  19. Events selection(con’t) Cut 2: number of jets≥1(con’t)

  20. Events selection(con’t) Cut 3: Highest momentum of 3μ>150 GeV.

  21. Events selection(con’t) Cut 3: Highest p of 3μ>150 GeV(con’t)

  22. Events selection(con’t) Cut 3: Highest p of 3μ>150 GeV(con’t)

  23. Events selection(con’t) Cut 4:scalar sum of 3μPtand Missing Et > 650 GeV* * last version: 3μPt>300 GeV

  24. Events selection(con’t) Cut 4:scalar sum of 3μPtand Missing Et > 650 GeV(con’t)

  25. Events selection(con’t) Cut 4:scalar sum of 3μPtand Missing Et > 650 GeV(con’t)

  26. Events selection(con’t) Cut 5: |mz0-91.17|<15 GeV, maximal momentum of 2μ> 70 GeV

  27. Events selection(con’t) Cut 5: |mz0-91.17|<15 GeV,maximal momentum of 2μ> 70 GeV (con’t)

  28. Events selection(con’t) Cut 5: |mz0-91.17|<15 GeV,maximal momentum of 2μ> 70 GeV(con’t) if there are two combinations of 3μ, |mz0 -91.17|</σ+|mtw-80.4|/σ is minimal to determine one

  29. Events selection(con’t) Cut 6: MtW<340 GeV

  30. Events selection(con’t) Cut 6: MtW<340 GeV(con’t)

  31. Events selection(con’t) Cut 6: MtW<340 GeV(con’t)

  32. Events selection(con’t) Cut 7: maximal p of jets>200 GeV

  33. Events selection(con’t) Cut 7: maximal p of jets>200 GeV(con’t)

  34. Events selection(con’t) Cut 7: maximal p of jets>200 GeV(con’t)

  35. Events selection(con’t) Cut 8: Mhwz>500 GeV Which is different from transverse mass

  36. Events selection(con’t) Mtwz Mhwz Cut 8: Mhwz>500 GeV(con’t)

  37. Events selection(con’t) Cut 8: Mhwz>500 GeV(con’t)

  38. Events selection(con’t) Cut 8: Mhwz>500 GeV(con’t)

  39. Events selection(con’t) Final Events and Significance Ns=19.1,Nb=2.6* in region of Mhwz>500 GeV, Significance: 7.3 for luminosity=50/fb, i.e. Significance: 5. for luminosity=23.2/fb, Significance =sqrt(2lnQ),Q=(1+Ns/Nb)Nbexp(-Nb). *last version:Nb=8.6

  40. Events selection(con’t) Sig Background Efficiency of cuts , here W1 mass = 700 GeV Evts= CR*50/fb

  41. Sig Events selection(con’t) Background Efficiency of cuts (con’t)

  42. Events selection(con’t) Sig Background Efficiency of cuts (con’t)

  43. Events selection(con’t) Events left and Significance as function of W1mass forluminosity of 50/fb , The same cuts are used for all masses.

  44. Events selection(con’t) Luminosity for Signal of 5 sigma

  45. Systematic uncertainties Trigger systematics: A uncertainty of 1% on Trigger Efficiency is assumed, uncertainties of events and uncertainty of luminosity significance for Lumnosity of 50/fb for 5 sigmal signal

  46. Systematic uncertainties Luminosity systematics: A uncertainty of 5%* on Luminosity is assumed, uncertainties of events and uncertainty of luminosity significance for Lumnosity of 50/fb for 5 sigmal signal last version: 10%

  47. Systematic uncertainties(con’t) Muon identification: μrecon., identification and track efficiency differences between the data and MC is assigned 2 % perμ, 6% for 3μ. uncertainties of events and uncertainty of luminosity significance for Lumnosity of 50/fb for 5 sigmal signal

  48. Systematic uncertainties(con’t) Jet Energy Scale: Pt difference between the data and MC is assigned 10 %. uncertainties of events and uncertainty of luminosity significance for Lumnosity of 50/fb for 5 sigmal signal

  49. Systematic uncertainties Cross Section uncertainty Signal cross section uncertainty first uncertainties are statistical errors , second are difference between PDF functons: cteq6l and cteq6m141

  50. Systematic uncertainties Cross Section uncertainty(con’t) Background cross section uncertainty Assume background cross section Uncetainty is 100.%

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