F. Richard, Prague Nov 2002

Towards LHC LC Synergy

Report from the LHC/LC (International) Study Group Conv: F. Paige G. Weiglein +Asian

F. Richard, Prague Nov 2002

What are our main goals?(personal view)

    We have to convince ourselves and other people (i.e. non h.e.

scientists, funding authorities, OCDE) that FLC results will influence the LHC program. This is SYNERGY. From present experience, the most convincing and direct example comes from the Tevatron program, for which upgrades of detectors, improved luminosity, improved algorithms are driven by the LEP/SLD/Tevatron prediction of a light Higgs.

We could try to build an analogue scenario, assuming that in ~2015 LHC will have to go for high luminosity and will upgrade its detectors. A timely FLC could therefore play an essential role in guiding this effort.

Not less important, for Science, is COMPLEMENTARITY, that is how much

do we increase the physicts potential with LHC+LC.

F. Richard, Prague Nov 2002

Main Topics Covered so far

3 Meetings took place since April: at StMalo, then twice at CERN ~100 participants ~30 studies

Mostly SUSY : LC precision crucial to sort out SSB scheme and to measure LSP.

Higgs sector within SUSY (precise BR and top mass crucial), the radion scenario

Some aspects on extended symmetries: LC needed to determine the origin of a Z’

Top physics, covered mostly by LHC contributions

F. Richard, Prague Nov 2002

What are the plans ?

Document with a written report + contributions by March 2003 i.e. before the Amsterdam meeting

Worldwide oriented work This report is a scientific document (+an

executive summary for a wider diffusion)Form an Editorial Board immediately Next meetings: - December 12/13, Fermilab - February 14, CERN

F. Richard, Prague Nov 2002

What is still needed

Build up complete and convincing Synergy+Complementarity cases

Strengthen participation of the ECFA/DESY community

Some of us went through the main topics (EWSB, SUSY, Xtradim, Extended groups, little Higgs) and through the possible scenarios and G. Weiglein will present these issues

evening discussion Sunday at 7 pm

F. Richard, Prague Nov 2002

Example of Complementarity

Finding SUSY is not enough, you need to know (Feng, Nojiri): Are the newly discovered particles really superpartners?

If not all superpartners are discovered, where are the rest of them? Synergy

Do the electromagnetic, weak, and strong forces unify?

Is a supersymmetric particle the dark matter?

How are the supersymmetric flavor and CP problems solved?

What is the scale of supersymmetry breaking?

What are the fundamental interactions at the Planck scale?

F. Richard, Prague Nov 2002

Example of Synergy

LHC finds a peak in l+l- What can it be ? LC can tell (couplings, mixing)

Knowing what it is, tell the LHC: E6, then look for the 8 new fermions e.g. D->Zd ZLR, then look for a higgs triplet Little Higgs, then look for colored fermion(s), new

scalars, vector bosons These new particles could be at the limit of detectability

of LHC, requiring improved detector, luminosity, algorithms

F. Richard, Prague Nov 2002

Conclusions

Essential activity: clarify our own ideas, convince the skepticals, strengthen our links to the LHC community

Crucial for political reasons More input needed Not much time left

Join the discussion on Sunday 19hJoin us !