1 / 20

Vector Resonance from Strong EWSB in pp → WW tt, tttt

CERN, Oct 27, 2005. Vector Resonance from Strong EWSB in pp → WW tt, tttt. Ivan Melo. M. Gintner, I. Melo, B. Trpisova (University of Zilina). Outline. Motivation for new vector ( ρ ) resonances: Strong EW Symmetry Breaking (SEWSB) Vector resonance model

konala
Download Presentation

Vector Resonance from Strong EWSB in pp → WW tt, tttt

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, Oct 27, 2005 Vector Resonance from Strong EWSB in pp → WWtt, tttt Ivan Melo M. Gintner, I. Melo, B. Trpisova (University of Zilina)

  2. Outline • Motivation for new vector (ρ) resonances: Strong EW Symmetry Breaking (SEWSB) • Vector resonance model • ρ signal in pp → ρtt→ WWtt + X ρtt → tttt + X

  3. EWSB: SU(2)L x U(1)Y→ U(1)Q Weakly interacting models: - SUSY - Little Higgs Strongly interacting models: - Technicolor

  4. Chiral SB in QCD SU(2)L x SU(2)R → SU(2)V , vev ~ 90 MeV EWSB SU(2)L x SU(2)R → SU(2)V , vev ~ 246 GeV

  5. WL WL→ WL WLWLWL → t tt t → t t t t t π = WL L = i gπMρ/v (π- ∂μπ+ - π+ ∂μπ-)ρ0μ + gt t γμ t ρ0μ+ gt t γμ γ5 t ρ0μ

  6. International Linear Collider: e+e- at 1 TeV ee ―› ρtt ―›WW tt ee ―› ρtt ―›tt tt ee ―› WW ee ―› tt ee ―› ννWW ee ―›ννtt 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

  7. Chiral effective Lagrangian 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+ρμ+ u+ i g’/6 Yμ) u ψL + b2ψRPb i γμ (u ∂μ – u ρμ+ u i g’/6 Yμ) u+PbψR + λ1ψL i γμ u+ Aμγ5 u ψL +λ2ψR Pλ i γμ u Aμγ5 u+PλψR BESS Our model Standard Model with Higgs replaced with ρ gπ= Mρ /(2 v gv) gt=gv b2/4+ … Mρ≈ √a v gv/2 t

  8. Low energy constraints Unitarity constraints WLWL → WLWL , WLWL → t t,t t → t t gv≥ 10 → gπ ≤ 0.2 Mρ(TeV) |b2 – λ2| ≤ 0.04 → gt≈ gv b2 / 4 gπ ≤ 1.75 (Mρ= 700 GeV) gt ≤ 1.7 (Mρ= 700 GeV)

  9. Partial (Γ―›WW) andtotal width Γtot of ρ

  10. Search at LHC: pp → W W t t + X J. Leveque et al. ATL-PHYS-2002-019: pp -> Htt -> WWtt MH =[120-240] GeV ρ • BRA: pp → ρtt→WWtt • σ(WWtt) = σ(ρtt) x BR(ρ->WW) • 2) Full calculation: pp → WWtt

  11. pp → W W t t + X (full calculation) 39 diagrams in gg channel No resonance background ρ ρ ρ

  12. CompHEP results: pp → W W t t + X ρ: Mρ=700 GeV, Γρ=4 GeV, b2=0.08, gv=10 SM: MH = 700 GeV ΓH = 184 GeV MWW(GeV) MWW(GeV) σ(gg) = 10.2 fb ―› 1.0 fb σ(gg) = 11.3 fb ―› 0.20 fb No resonance background: σ(gg) = 0.037 fb Cuts: 700-3Γρ < mWW < 700 +3Γρ (GeV) pT > 100 GeV, |y| < 2

  13. Total cross sections for ρtt and WWtt BRA: σ(WWtt) = σ(ρtt) x BR(ρ->WW)

  14. |N(ρ) – N(no res.)| √(N(no res.)) R = ≈ S/√B > 5 BRA Full calc.

  15. tttt vs WWtt BRA BRA

  16. Conclusions • New strong ρ-resonance model • pp → W W t t + Xpp → t t t t + X at LHC • R values up to a few 100 (before t,W decays and detector effects) • Backgrounds pp → tt, W + jets, Z + jets, … ? Similar work on pp → t t t t + X : T.Han et al, hep-ph/0405055

  17. Search at Hadron Colliders Mρ=700 GeV, Γρ=12.5 GeV Tevatron: p + p ―› t + t σS= 1.2 fb σB = 8 306 fb LHC: p + p ―› t + t σS = 22.7 fb σB = 752 000 fb

  18. pp → ρt t + X(8 diagrams in gg channel) BRA: σ(WWtt) = σ(ρtt) x BR(ρ->WW)

  19. pp → Htt (SM) : σgg(MH = 100) = 943 fb σgg(MH = 700) = 8.2 fb σuu(MH = 100) = 98 fb σuu(MH = 700) = 0.3 fb

More Related