A Linear Collider Run Scenario

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A Linear Collider Run Scenario
Choose a physics scenario that is CONSERVATIVE
in the sense that it has many particles and
thresholds to explore. Assume electron, but not
positron polarization again conservative
! The purpose of the exercise is to show that a
good physics program is achievable in a
reasonable length of time. Based upon guesses
from talks of R. Brinkmann and T. Raubenheimer
we imagine the luminosity curve is Year
1 2 3 4 5 6 7 Yrly Lum(fb-1) 10 40 100
150 200 250 250 total program 1000 fb-1 at
500 Gev
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Susy model Assume mSUGRA model with many
sparticles accessible at 500 GeV. m_0 100
GeV m_1/2 200 GeV A_0 0 tan b
3 m gt 0 (This model is now ruled out
from recent data, but something like it with
larger tan b and finite A_0 yields a similar
sparticle mass spectrum) Note all Susy
models are idiosyncratic cross sections,
branching ratios, masses, sensitivities to Susy
parameters vary strongly with specific parameter
choices. Higgs take m_Higgs 120 GeV
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Sparticle masses Selectron_R 132
GeV Selectron_L 176 Sneutrino_e 161 Smuon_R
132 Smuon_L 176 Sneutrino_mu 161 Stau_1 131
Stau_2 177 Sneutrino_tau 161 Chargino_1 128 C
hargino_2 346 Neutralino_1 72 Neutralino_2 130
Neutralino_3 320 Neutralino_4 348
Squarks, gluino out of reach at 500 GeV
(m(stop_1) 377 GeV
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• Susy particle mass determinations.
• Obtain masses to O(GeV) precision from end points
  at energy above threshold ( 2 such energies 320
  500 GeV)
• Scan selected thresholds for improved precision
  (use e-e- for selectron_R)
• Use Snowmass and previous studies for mass
  precision
• U. Nauenberg, M. Dima, J. Barron, A. Johnson, L.
  Hamilton, D. Staszak, T. Turner for end point
  precisions
• G. Wilson for chargino threshold scan
• H.-U. Martyn G. Blair, hep-ph/9910416 for
  scans
• J. Feng M. Peskin, hep-ph/0105100 for e-e-
  selectron
• H. Baer, A. Belyaev, J. Mizukoshi, X. Tata for
  sneutrino scans
• (not all studies at exactly same Susy point or
  with same BRs or backgrounds!)
• Backgrounds, resolutions, Beamsstrahlung
  approximately taken into account (backgrounds
  vary considerably with model point!)
• Scan luminosities are for all points in a scan
  location of points not optimized

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Run Plan for 1000 inverse fb
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Susy particle mass precisions from end point
determinations Snowmass studies by Colorado
group
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Estimated mass precision for Sparticles



Sneutrino mass determinations are quite
sensitive to specific Susy model (BR to lepton
chi), and suffer from low rates. Studies
differ on sneutrino mass precision.
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Determination of mSUGRA parameters (estimated)
m_0 100 /- 0.1 GeV (largely
determined by selectron_R)
m_1/2 200 /- 0.2 GeV (largely
determined by charginos)
A 0 /- 10 GeV (largely
determined by stau_1,2)
tan b 3 /- 0.03 (largely
determined by chi, chi0 )
The TeV scale Susy parameters and the RGE
extrapolation to the GUT scale mSUGRA parameter
errors need further investigation here scaled
from TESLA TDR study of same point, assuming
errors from cross sections and masses both scale
statistically. It will also be useful to
estimate the attainable Susy coupling relation
precision, and to estimate cross section
accuracies more carefully. Attention should also
be given to how well the quantum numbers of the
Sparticles can be determined.
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For the scenario chosen, the LHC will also
produce most of the sparticles, and because of
the favorable decay chains, can do precision mass
measurements leading to good determination of
mSUGRA parameters. LHC squark masses enabled by
LC determination of an absolute scale will give
needed information on threshold corrections for
gaugino mass parameters. For less rich scenarios
without most of the gauginos, limits on
chargino/neutralino mixing parameters will limit
mSUGRA parameter determination.
(Murayama) However, this study of precision of
mass determinations at the Linear Collider is
illustrative that a precision program can be
performed within reasonable time.
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Higgs measurements (number of ZH events
equivalent to 650 fb-1 at 350 GeV or
1350 fb-1 at 500 GeV ) (scaled from Tesla
TDR and LC Resource book M. Battaglia, G.
Bernardi, R. Cahn)
Top quark measurements Top mass /- 150 MeV
(limited by QCD uncertainties) Top width
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Conclusion
A high precision program is achievable with 1000
fb-1 (7 years) of data, determining Susy
masses, underlying Susy parameters and Higgs
studies. Details of Susy results are dependent
on the specific Susy parameters. For the case
studied, sneutrino masses are not precisely
determined.