INTERNATIONAL PROPOSAL HIGGS self couplings Experimental study Durham Sept. '04 Pierre Lutz

International exp. study on hhh Global (all 3 regions involved) Exp. : feasibility study, but phenomenologists welcome hhh : important benchmark remember Veltman at Desy, Paul Grannis at Snowmass, … Durham Sept. '04 Pierre Lutz

Durham Sept. '04 Pierre Lutz Today status First study (Pascal Gay, Pierre Lutz et al.) in 1998-2000 Mainly 1 cms energy (500 GeV) (partly extended to 800 GeV) Only SM Higgs, with masses up to 140 GeV and only higgsstrahlung. H decays only into bbbar Result : error on lambda = 22% Durham Sept. '04 Pierre Lutz

Durham Sept. '04 Pierre Lutz Today status (cont.) M. Battaglia made it for CLIC case (Snowmass) A Berkeley student added a few channels (Snowmass) S. Yamashita presented at LCWS04 the 1000 GeV case. Durham Sept. '04 Pierre Lutz

Weak points of these studies Simplified simulations, when not pure generators output. Beamstrahlung effects not always taken into account, resulting in an overestimation of the kin. fits perf. Rather simplified b-tagging No study for Higgs mass above 140 Use only of Higgsstrahlung Durham Sept. '04 Pierre Lutz

Durham Sept. '04 Pierre Lutz Proposal « Full » simulation(s?) some exist : should be made public At least 500 and 1000 GeV For H masses up to 200 Gev or more ZHH with H -> WW simulations need generators experts For all H and Z decays Durham Sept. '04 Pierre Lutz

Durham Sept. '04 Pierre Lutz PURPOSE To allow a review (and pinpoint weaknesses) of * status of generators * status of simul. Packages * test of kin. fits/pairings * test the W-Z separation * test of the b-tagging algos on a crucial benchmark ! Provide a reliable detector benchmark. To start working « global » Durham Sept. '04 Pierre Lutz

Durham Sept. '04 Pierre Lutz Practical P. Gay (and Clermont group), P.L. S. Yamashita (alone ? for Asia) the Hamburg group (tools) … are ready to start the adventure Please join (ideas and manpower) generators/simulations experts detector performance experts Distribution list, and first meeting at next workshop Durham Sept. '04 Pierre Lutz