Dual-Readout Calorimeter: DREAM

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Dual-Readout Calorimeter DREAM

• Richard Wigmans, Nural Akchurin,
• Heejong Kim, Hans Paar, John Hauptman

CERN H2 beam summer 2003
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Dual Readout - CerenkovScintillation in same
event

• Fluctuations in pi-zero content of hadronic
  showers limits energy resolution, introduces a
  constant term, and results in a non-linear
  calorimeter response
• Cerenkov light is largely generated by electrons
  from photons from pi-zeros, and therefore
  measures the pi-zero content event-by-event
• Scintillation light measures all charged tracks

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Basic unit 4mm x 4mm Cu tube
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Beam view of module hexagons define
geometric channels
Module is 2 meters deep in beam direction
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Rear of module Cerenkov and Scintillation fibers
go to separate R725 Hamamatsu PMTs
Bright light shining through 2 meters of Cu
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H2 Beam at CERN not quite to scale
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Pre-Shower Detector clean IDs
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Cerenkov and Scintillation pulse height
distributions
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Cerenkov vs. Scintillation
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EM shower fraction distribution
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(QS)/E
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S corrected by Cerenkov-measured EM fraction
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Before After EM fraction correction
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Pion Energy Resolution
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Distributions of center-of-light
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Before After Cerenkov-measured EM fraction
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Energy resolution of interaction jets