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

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Phantom Ballestrero, Belhouari,Bevilacqua,E.M. Dedicated event generator Complete 26 O(α 6 )+O(α 4 α s 2 ) pbar, e + e -- p-p, p-pbar, e + e -- Complete set of reactions up to pp 4l2j, ee 2l4j At LHC: q 1 q 2 f 1 f 2 f 3 f 4 f 5 f 6 O(α 6 )+O(α 4 α s 2 ) gg f 1 f 2 f 3 f 4 f 5 f 6, gqgq f 1 f 2 f 3 f 4, qqgg 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 Phase1.0 Accomando,Ballestrero,E.M. hep-ph/

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qqVV prod VV scattering Higgs top VV couplings

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Exact vs VVqq-Prod Decay uuuuqqμν Single process qq=u-dbar,c-sbar mh=500GeV MADEVENT: qqWV Decay Tuned comparison Could produce exact result

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

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Models of EWSB Electroweak Chiral Lagrangian Butterworth,Cox,Forshaw PRD65(02)96014 Fabbrichesi,Vecchi hep-ph/ many others Expand LL LL Amp in partial waves M= j a j (s) Pj (cos( ϑ )) SS =1 |a j (s)|1 Low Energy Th. M (VVVV) s/v 2 No H Unitarization: one example a j = a 0j /(1-ia 0j ) a 0j s Small s LET Large s a j 1 NOT UNIQUE!! Works well in ππ

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Models of EWSB 2 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 Model Independent Low Energy parametrization of composite Higgs models Giudice,Grojean,Pomarol,Rattazzi hep-ph/ Barbieri,Bellazzini,Rychkov,Varagnolo arXiv: Additional dynamics,dimensions …….

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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/ qq4qlv ( EW) M(VW)>800GeV +p T +E+η+M ij cuts

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qq4qμ + μ -- ( EW) M(VZ)>800GeV +p T +E+η+M ij cuts Accomando,Ballestrero,Belhouari,Maina PRD 75:113006,2007 hep-ph/ fb -1 |η V |< 2

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Looking for Mr. V Boson Butterworth, Ellis, Raklev hep-ph/

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qq4qlv O(α 6 )+O(α 4 α s 2 ) Ballestrero, Bevilacqua,E.M. WVjj Wjjjj

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

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Conclusions Studying EWSB through VV scattering is hard Semileptonic channels essential New techniques for reconstructing hadronic Vs needed Plans Complete qq4qlv Alternative models of EWSB

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Backup slides

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Boson-Boson scattering and Unitarity

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Selection 4qμν CMS Note

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Selection 4qeν CMS Note

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Selection 4qeν continued

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Efficiency

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