1 / 16

BESS Model Resonance in the pp W + W tt + X Channel at LHC

CERN, Nov 1, 2006. BESS Model Resonance in the pp W + W tt + X Channel at LHC. M. Gintner, I. Melo, B. Trpi šová University of Žilina. Outline BESS Model Vector Resonance ρ Cross sections for pp →WWtt + X (CompHEP calculation) reconstruction

onan
Download Presentation

BESS Model Resonance in the pp W + W tt + X Channel at LHC

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. CERN, Nov 1, 2006 BESS Model Resonance in the pp W+W tt + X Channel at LHC M. Gintner, I. Melo, B. Trpišová University of Žilina

  2. Outline BESS Model Vector Resonance ρ Cross sections for pp →WWtt + X (CompHEP calculation) reconstruction (CompHEP, Pythia, Atlfast, Root)

  3. t t t 1,2 1,2 1,2 π = WL are BESS coupling constants is the SU(2)L coupling constant v is EW scale (246 GeV) R.Casalbuoni et al. Phys.Lett. B155 (1985) 95;M.Gintner, I.Melo, B.Trpisova, Acta Phys. Slovaca, 56(2006)1

  4. Large Hadron Collider: pp at 14 TeV pp ―› ρtt ―›WW tt pp ―› ρtt ―›tt tt pp ―› WW pp ―› tt pp ―› jj WW pp ―› jj tt

  5. 39/8 diagrams in the dominant gg channel ρ No-resonance background ρ ρ

  6. CompHEP results: pp → W W t t + X ρ: Mρ=700 GeV, Γρ=4 GeV, b2=0.08, gv=10 39 diagrams 8 diagrams MWW(GeV) gπ=Mρ/2vgv gt1,2= gv b2/4 σ(gg) = 10.2 fb ―› 1.0 fb Cuts: 700-3Γρ < mWW < 700 +3Γρ (GeV) pT (t) > 100 GeV, |y(t)| < 2 No resonance background: σ(gg) = 0.037 fb

  7. l jjbjjbjj reconstruction (CompHEP, Pythia, Atlfast, Root) Athena 9.0.3 One charged lepton channel: 40% of events electron > 30 GeV muon > 20 GeV of Cuts: GeV mass of the W: jets > 25 GeV 50% b-tagging efficiency Reconstruction criterion

  8. 8 diagrams 39 diagrams Lum=100/fb Lum=100/fb 12.2 events 2.4 events number of events/17 GeV Distribution in invariant mass of WW pair (ρ →WW) ρ: Mρ=700 GeV, Γρ=4 GeV, b2=0.08, gv=10 Pz(ν) chosen correctly in 61.5 % of events number of events/17 GeV

  9. 39 diagrams 8 diagrams Mass of the W boson Lum=100/fb Lum=100/fb 12.2 events 2.4 events number of events/0.6 GeV number of events/0.6 GeV Mass of the top quark Lum=100/fb Lum=100/fb 12.2 events 2.4 events number of events/2.5 GeV number of events/2.5 GeV

  10. ρ: Mρ=1000 GeV Γρ=26 GeV Lum = 100 fb-1 12.8 events number of events/32 GeV

  11. 1. Can we improve WWtt reconstruction ? L = 100/fb 2.4 events 8 diagrams versus 2. 8 diagrams

  12. Appendix

  13. BESS (Breaking EW Symmetry Strongly) Model SU(2)L x SU(2)R global, SU(2)L x U(1)Y local L = Lkin + Lnon.lin. σ model -a v2 /4 Tr[(ωμ + i gvρμ . τ/2 )2] + Lmass+ LSM(W,Z) +b1ψL i γμ (u+∂μ – u+i gvρμ . τ/2+ u+ i g’/6 Yμ) u ψL + b2ψRPb i γμ (u ∂μ – u i gvρμ . τ/2 + u i g’/6 Yμ) u+PbψR + λ1ψL i γμ u+ Aμγ5 u ψL +λ2ψR Pb i γμ u Aμγ5 u+PbψR Our model Standard Model with Higgs replaced with ρ ωμ = [u+(∂μ + i g’/2 Yμτ3)u + u(∂μ+ i g Wμ . τ/2)u+]/2 Aμ = [u+(∂μ + i g’/2 Yμτ3)u - u(∂μ+ i g Wμ . τ/2)u+]/2 u = exp(i π . τ/2v) ψL = (tL,bL) Pb = diag(1,p) Mρ≈ √a v gv/2 v ≈ 246 GeV … EW scale

  14. Total width Γtot of ρ

  15. EWSB: SU(2)L x U(1)Y→ U(1)Q Weakly interacting models: - SUSY - SM (light) Higgs Strongly interacting models: - Technicolor A new strong vector resonanceρas an isospin triplet ( ) → BESS

More Related