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• Discussion How could ILC influence LHC triggers?
• Our first report gave many examples of
• how LHCILC data interpreted together could give
  new insights
• how ILC data could be fed back into the LHC data
  analyses
• All of this could in principle be done even after
  the completion of LHC
• data taking (although it will certainly work
  better if both machines are
• alive simultaneously).
• Already in the very first discussion about
  LHC/ILC studies, it was realized
• that an even clearer argument for concurrent
  running could be made if
• a scenario should arise where information from
  ILC can be used to
• modify/upgrade LHC triggers and therefore
  optimize the acceptance for
• certain new physics signals.

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• In those first discussions some people felt that
  constructing such a scenario
• might be too artificial.
• Nevertheless, this question came back to us by
  people who read our first
• report.
• Should we make another attempt to work into this
  direction?
• In order to make it a success (given limited
  human resources)
• we should identify one promising scenario to work
  with
• We should find a small team consisiting at least
  of
• a theory expert for the chosen scenario
• an LHC trigger (simulation) expert
• an ILC contact person
• It is clear that in particular without person 2
  the project will fail.

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Identifying a scenario 2 suggestions from J.
Ellis
Suppose that the LC discovers a (meta)stable
massive charged particle, such as a stau in a
model with a gravitino LSP. It might be that the
LHC experiments would/could modify their trigger
and/or even their TOF systems so as to collect
these more efficiently. Alternatively,
suppose that the LC discovers a massive charged
particle that decays rapidly into a lighter
neutral particle with a very small mass
difference, as occurs in models with a neutralino
LSP in the coannihilation region. Perhaps the LHC
experiments would/could modify their lepton p_T
triggers (replacing them by some other event
characteristic? at the expense of some
other triggers?) so as to collect these more
efficiently.
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Identifying a scenario Another idea MSSM Higgs
sector with CP-violation LEP cannot exclude a
very light (mainly CP-odd) Higgs Detection of H2
seems guaranteed at LHC and ILC but H1 may be
more difficult. Question could LHC see a
low-mass (20-50) GeV bbbar resonance if ILC
tells its mass?
mH1(GeV)
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Other ideas from previous CERN meeting

• heavy stable charged particles ( R- hadrons)
• ILC input charginos/neutralinos (not too light
  but not too heavy)
• - then use GUT relation to
  predict m(gluino)
• heavy charginos with low-pt leptons ?
• ILC can predict chi03/chi04/chi2 from
  chi01/chi02/chi1
• if cascades at LHC are complicated
  mass/coupling predictions may help
• going down in energy ?
• (move from g-dominated to q-dominated pdfs to
  reduce bkgd if
• low-mass hadronic resonance exisits)
• very light rare di-lepton resonance (e.g.
  gg-gtA-gt mumu in CPV MSSM)
• Z with BR(Z-gthadrons) 1
• open a mass-window in jet-jet trigger

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your input