First%20look%20at%20srest

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First look at srest

• Peter Križan
• Friday meeting, Jan 27 2006

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Impact of srest

• With a aerogel thickness of 4cm
• strack from 4.1mrad -gt 4.8mrad
• srest0 srest8mrad
• strack from 4.7mrad -gt 4.1mrad
• 2 layers 3 layers
• -gt Have to understand the origin of srest!

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srest vs. distance MD6MD9

• Full sigma, AB, BA
• srest , AB, BA

srest7mrad
srest0mrad
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srest vs. distance KMD4-13

• Full sigma, AB, BA
• srest , AB, BA

srest7mrad
srest0mrad
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Contribution of the tracking error to srest

• Simple model error in coordinates at z0 and z4
  (MWPCs), multiple scattering only in the detector
  material.
• Motivation walls of the box (at z1 and z3) are
  too close to the MWPC and to the aerogel to have
  a significant effect.

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Tracking error
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Tracking error use BT04 data to tune the
material at z2
Best with rather high material - 0.7 X0 -
probably a consequence of material or the
imperfection of the model.
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Tracking error
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Tracking error impact of material at z2
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Is srest composed of a constant tracking error?
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Is srest composed of a constant tracking error?
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Status

• Data analysis relies mostly on what I did during
  the beam test, so a further tuning of geometric
  constats might yield slightly smaller values of
  sigma -gt to be done in the next days