LCWS-Paris

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LCWS-Paris

• Presentation at the LCWS-Paris
• Meeting
• SUSY Analysis of Sleptons, Chargino
• Problems, Solutions, Improvements
• April, 2004

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• THE GROUP
• Shirley Choi, Bradford Dobos, Tyler Dorland,
  Eric Erdos,
• Jeremiah Goodson, Jack Gill, Jason Gray,
• Andrew Hahn, Eric Kuhn, Alfonso Martinez,
• Kyle Miller, Uriel Nauenberg, Joseph
  Proulx,
• Jesse
  Smock

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• ACTIVITIES
• Simulation of Supersymmetry. New method to
  overcome the negative effects of beamstrahlung
  and bremmstrahlung.
• The Benefits of Positron Polarization.
• Resolution on M0 , M1/2 from mass measurement

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• Simulation of Selectron Production
• Case Study
• Consider Case SPS3 , M1/2 400 GeV, M0 90
  GeV.
• Mass of eR 178.3 GeV, Mass of eL 287.1 GeV,
  Mass of ?01 160.6 GeV.
• Compare Fits with Beam and Bremmstrahlung and
  without.
• We use the e - e - Energy Spectra Substraction
  Technique to remove Standard Model Background.

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• CM Energy Distribution with Beamstrahlung

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• Selectron Production
• e - e - Energy
  Spectra

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• Resultant Fits to Energy Edges
• No Bremm
  Bremm

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• New Method to Determine Masses
• Compare Energy Spectrum to those Generated with
  different parameters encompasing the correct one.
• Do a Chi Square Fit to the Spectra Comparison.
• Choose the minimum and determine the masses.

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M1/2 400 , M0 90 expec. value.
M1/2 1.5 from 400, M0 90
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• M1/2 vs M0 curves for Msel L values M1/2 vs M0
  curves for Msel R values

Not physical
Not physical
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?

• M1/2 vs M0 curves for M (c10 )

No dependence on tan(? )
Not physical
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• Chi Square Fit for the SPS3 Snowmass Point
• 
  
• 
  M1/2(expec.) 400 GeV
• 
  M1/2(fit)400.220.19 GeV
• 
  M0 fixed at 90 GeV
• 
  tan(? ) fixed at 10

-0.54
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• Chi-Square Fits for the SPS1 Snowmass Point
• 
  M1/2 250 GeV
• 
  M0 100 GeV
• 
  tan(? ) fixed at 10
• 
  No depend. On
• 
  tan(b)

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• Chi-Square Fits for the SPS1 Snowmass Point
• 
  M1/2 250 GeV
• 
  M0 100 GeV
• 
  tan(? ) fixed at 10
• 
  No depend. on
• 
  tan(b)

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• e e - ? ? 2 ? 2
• ? Z0
• Z0 ? l l - one decay
• Z0 ? q q other decay

?

0
0
?
?
? 2
? 1
0
0
?
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• Energy Distribution of the Z

TAIL IS SUSY BKGD
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• M1/2 vs tan(b) for Values of
  ?2 Masses

0
Not Physical Solution
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• By doing an overall fit to the MSSM
• parameters you can include the SUSY
• background in the fit.
• In the case of the Energy Spectra of Neutralinos
• Decay Secondaries there is always
• other SUSY Decay Background

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SPS4
M1/2 300 GeV
tan(b) 50
F I T
M1/2 303 9 GeV
- 6
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?
?
?
?

• e e- ? ?20 ?20 ?20? Z0 ?10

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• Dependence of ?20 Mass on tan(? )

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• Effect of Positron Polarization
• What do we observe if we have positron
• polarization. We studied 80 e -, 80 e.
• Applied to Selectrons and Smuons.

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?
?

• Electron, Positron Energy Spectrum from e
  e - ? all e e
• e- Spect.e - 80R e Spect. e-
  Spect.e - 80R e Spect.
  

e 80 R
e 80 L
e 0 pol.
e 0 pol.
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?
?

• Muon Energy Spectrum from e e - ? m m
  
• e - 80 R e 80 L
  e 80 L e 80 R

WW BKGD
WW BKGD
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LCD-ALCPG

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LCD-ALCPG

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LCD-ALCPG

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LCD-ALCPG