PHANTOM Update Ezio Maina U of Torino Physics

PHANTOM Update Ezio Maina U. of Torino Physics at Te. V Colliders Workshop - Les Houches 2007

Phantom Ballestrero, Belhouari, Bevilacqua, E. M. § § § § § Dedicated event generator Complete 2→ 6 O(α 6)+O(α 4αs 2) p-p, p-pbar, e+e-Complete set of reactions up to pp → 4 l 2 j, ee → 2 l 4 j At LHC: q 1 q 2→f 1 f 2 f 3 f 4 f 5 f 6 O(α 6)+O(α 4αs 2) gg → f 1 f 2 f 3 f 4 f 5 f 6, gq→gq f 1 f 2 f 3 f 4, qq→gg f 1 f 2 f 3 f 4 Exact matrix elements. No production⊗decay or EVBA Fast One-shot: generates unweighted events for all processes simultaneously Efficient: good mapping of phase-space Multichannel + Vegas q 1 q 2→q 1 q 2 q 3 q 4 lv covered in Phase 1. 0 Accomando, Ballestrero, E. M. hep-ph/0504009

qq. VV prod VV scattering Higgs top VV couplings

Exact vs VVqq-Prod⊗Decay uu→uuqqμν qq=u-dbar, c-sbar Single process mh=500 Ge. V MADEVENT: qq. WV⊗Decay Could produce exact result Tuned comparison

VV scattering with PHANTOM o Light Higgs ➙ VV weakly coupled Higgs Found ➙ check VV scattering Are SM predictions verified? o Heavy (No) Higgs ➙ VV strongly coupled Higgs Not Found ➙ check VV scattering What restores Unitarity?

Models of EWSB Electroweak Chiral Lagrangian Butterworth, Cox, Forshaw PRD 65(02)96014 Fabbrichesi, Vecchi hep-ph/0703236 many others o. Expand LL → LL Amp in partial waves M=∑j aj (s) Pj (cos(ϑ)) o. SS†=1 ⇒ |aj(s)|≤ 1 o. Low Energy Th. M(VV→VV)∝s/v 2 No H Unitarization: one example aj = a 0 j /(1 -ia 0 j) a 0 j∝s NOT UNIQUE!! Works well in ππ Small s ⇒ LET Large s ⇒ aj→ 1

Models of EWSB 2 Additional dynamics, dimensions ……. Model Independent Low Energy parametrization of composite Higgs models Giudice, Grojean, Pomarol, Rattazzi hep-ph/0703164 Barbieri, Bellazzini, Rychkov, Varagnolo ar. Xiv: 0706. 0432 o o Higgs low energy “remnant” of High Energy Strong Dynamics Severely constrained by EW Precision Tests Additional states may appear as resonances (Model dependent) Reduced HVV couplings ➙ Partial restoration of Unitarity up to the High Energy scale

qq→ 4 qlv(EW) M(VW)>800 Ge. V +p. T+E+η+Mij cuts Small sensitivity to MH in SM range ⇒ SM predictions well defined. Not just counting exp Accomando, Ballestrero, Bolognesi, E. M. , Mariotti JHEP 0603(2006)093 hep-ph/0512219

qq→ 4 qμ+μ-- (EW) M(VZ)>800 Ge. V +p. T+E+η+Mij cuts Accomando, Ballestrero, Belhouari, Maina PRD 75: 113006, 2007 hep-ph/0603167 100 fb-1 |ηV|< 2

Looking for Mr. V Boson Butterworth, Ellis, Raklev hep-ph/0702150 W jets Jet in W+jet 70<M<90 Ge. V p. T > 250 Ge. V Alternatives?

qq→ 4 qlv O(α 6)+O(α 4αs 2) Ballestrero, Bevilacqua, E. M. WVjj ✔ Wjjjj ✘

Closer to the real world Preliminary CMS Note 2007/005 Torino+ Milano CMS Group+TH 430 fb-1 needed for S/B 1/2=5 in 4 qev FAMOS Bkg: Alpgen+Madevent

Conclusions o o o Studying EWSB through VV scattering is hard Semileptonic channels essential New techniques for reconstructing hadronic V’s needed Plans Complete qq→ 4 qlv o Alternative models of EWSB o

Backup slides

Boson-Boson scattering and Unitarity

Selection 4 qμν CMS Note

Selection 4 qeν CMS Note

Selection 4 qeν continued

Efficiency