Towards LHC LC Synergy

1
Towards LHC LC Synergy

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

2
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
  LHCLC.

3
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

4
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

5
What is still needed

• ? Build up complete and convincing
  
• SynergyComplementarity 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

6
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?

7
Example of Synergy

• LHC finds a peak in ll-
• 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-gtZd
• 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

8
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 19h
• Join us !