WW Fusion in Higgsless Models at the LHC

WW Fusion in Higgsless Models at the LHC Rahul Malhotra University of Hawaii at Manoa PHENO 2006

Higgsless Models • Theories contain tower of heavy Te. V-scale vector bosons - Vi±, Vi 0 • O(E 4) and O(E 2) terms in the WW, WZ scattering amplitudes are cancelled by exchange of these particles, without invoking a Higgs boson • In 5 D theories symmetry-breaking is achieved via boundary conditions on an interval • Unitarity violation postponed to Λ ~ 5 – 10 Te. V [ Cacciapaglia, Csaki, Grojean, Pilo, Murayama, Terning hep-ph/0305237, 0308038, 0401160, 0409126 ]

← Resonance [ Chivukula, Dicus, He, Nandi hep-ph/0111016, 0302263, 0402222; Csaki hep-ph/0510275 ] SUM RULES :

WZ → V 1± → WZ • The sum rules were found saturated by just one resonance V 1± : • SM fermions can be decoupled from excited KK modes* • “Gold - plated” channel: 2 forward jets + 3 l + missing ET • M upto 1 Te. V covered by 60 fb-1 of luminosity [ Birkedal, Matchev, Perelstein hep-ph/0412278 * Cacciapaglia et al hep-ph/0409126 ]

WW → V 10 → WW LHC Signal: 2 forward jets + final state W Decays: 1. ll 2. l jj • Cleaner Signal • Cannot reconstruct mass • More background sources • Can reconstruct mass

Backgrounds for eμ - channel Top production dominates background even after cuts • • tt + jets EW WWjj in SM QCD WWjj production + jets ~ 50 -70% ~ 20 -40% ~ 5 -10% < 5%

Controlling Backgrounds: • 2 separated forward jets: | 1 - 2| > 4. 4 • b, Minijet Veto in central region for ET > 20 Ge. V. • Require forward jets MJJ > 700 Ge. V • Reconstruct (gentle) resonance in ETmax (e, μ) > 85 Ge. V for MV = 500 Ge. V ↓ > 140 Ge. V for MV = 1 Te. V • Real reconstruction

More on central jet veto • Adopt similar methodology to that used for heavy higgs H → WW searches • For example for tt + jets: - Calculate tt, tt + 1 j, tt + 2 j - Use higher order calculation to estimate central jet activity - Veto central b jets with ET > 20 Ge. V [ Rainwater, Zeppenfeld hep-ph/9906218 ]

LHC Cross-sections (fb), MV = 725 Ge. V CUTS V 10 jj WWjj (EW) WWjj (QCD) tt + jets 2 forward jets + ET(l) > 20 Ge. V, | (l)| < 2. 5 0. 668 2. 84 4. 71 1036 MJJ > 700 Ge. V 0. 602 2. 64 2. 45 414 Veto central b jets / minijets 0. 522 2. 06 0. 637 6. 54 ETmax(e, μ) > 110 Ge. V 0. 418 0. 803 0. 113 1. 11

RESULTS MV Discovery Range (Ge. V) 30 fb-1100 fb-1 300 fb-1 5 366 535 723 4 420 610 816 3 503 717 960 • Challenging • Can be improved by - including ee, μμ + neutrinos channel - more refined cuts • Aim to extend 5 to 1 Te. V at 300 fb-1