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

2. 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. ' Pierre Lutz

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

4. 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. ' Pierre Lutz

5. 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. ' Pierre Lutz

6. 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. ' Pierre Lutz

7. 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. ' Pierre Lutz

8. 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. ' Pierre Lutz