HU Z analysis update

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HUZ analysis update
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Remember Princeton

• Cut on beam current and on pcal
• Normalization to beam current and photonflux
• Different methods of signal-background
  combination (C1, D)
• Tested pcal-correction for steering effect
• Determined energy depostion by a double gaussian
  fit
• 
  for example

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BG subtr. Edep in the CsI crystals
Sum of two Gaussians with the same meanvalue is
fitted to the Energydistribution
Ffit G1(µ,s1) G2(µ,s2)
µ
ns,nb - of Signal/Background events in the
fit FWHM - full width at half max. of the final
fit
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Remember Princeton

• Cut on beam current and on pcal
• Normalization to beam current and photonflux
• Different methods of signal-background
  combination (C1, D)
• Tested pcal correction for steering effect
• Determined energy depostion by a double gaussian
  fit
• Calculated asymmetry from cycle pair asymmetries
• 
  ?

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Asymmetries Ai
Linear fit of Ai
A ?A ?2 / ndf ?A?
Meth. C1 1.07 0.05 765 / 220 0.10
Meth. C1 Cut2 1.09 0.07 599 / 220 0.11
Meth. D 1.03 0.06 407/ 220 0.08
Meth. D Cut2 1.02 0.07 392 / 220 0.09
define a figure of merit
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Asymmetries Ai
Linear fit of Ai
A ?A ?2 / ndf ?A? A?bar ?A?bar
Meth. C1 1.07 0.05 765 / 220 0.10 1.07 0.08
Meth. C1 Cut2 1.09 0.07 599 / 220 0.11 1.11 0.09
Meth. D 1.03 0.06 407/ 220 0.08 1.00 0.07
Meth. D Cut2 1.02 0.07 392 / 220 0.09 0.97 0.07
define a figure of merit
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Asymmetry Asymmetry Asymmetry Asymmetry Asymmetry Asymmetry Asymmetry Asymmetry Asymmetry Asymmetry Asymmetry Asymmetry
BC BC BC BC corr. BC corr. BC corr. Ag1Sic Ag1Sic Ag1Sic Ag1Sic corr. Ag1Sic corr. Ag1Sic corr.
100 0,57 0,16 0,48 0,14 0,56 0,16 0,46 0,14
120 0,89 0,08 0,83 0,08 0,89 0,08 0,83 0,07
140 1,03 0,06 0,95 0,06 1,04 0,06 0,96 0,06
160 0,83 0,08 0,79 0,07 0,89 0,08 0,88 0,07
180 0,88 0,18 0,83 0,16 0,86 0,18 0,82 0,16
180ff 0,98 0,13 0,99 0,11
160el 1,31 0,05 1,28 0,04 1,32 0,05 1,29 0,04
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Princeton state
HUZ and Tel Aviv
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• In september it was proposed to find a method,
  that
• is simpler to explain
• avoids fits as much as possible
• is just more straight foreward

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Proposed method

• Determine asymmetries from ajacent cycle pairs

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Pairing of superruns
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Proposed method

• Determine asymmetries from ajacent cycle pairs
• Cut on the beam current (both cycles as one)
  -gt select a 3s range

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Toroid6130
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Proposed method

• Determine asymmteries from ajacent cycle pairs
• cut on the beam current (both cycles as one)
  -gt select a 3s range
• Separate Undulator ON and Undulator OFF events

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Distribution in the central crystal
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Distribution in the central crystal (calibrated)
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Proposed method

• Determine asymmetries from ajacent cycle pairs
• Cut on the beam current (both cycles as one)
  -gt select a 3s range
• Normalize each event -gt Photonflux (Ag1Sic)

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Normalization to the Photonflux
Undulator ON
Undulator OFF
Every event is normalized to The readings of
Ag1Sic by
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Proposed method

• Determine asymmetries from ajacent cycle pairs
• Cut on the beam current (both cycles as one)
  -gt select a 3s range
• Normalize every event -gt Photonflux (Ag1Sic)
• Subtract background from signal (event by event)

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Background subtraction
Combine all signal events with all background
events -gt (Meth. D)
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Combining Signal and Background events
N Ns Nb
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All crystals 2676_1
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Proposed method

• Determine asymmetries from ajacent cycle pairs
• Cut on the beam current (both cycles as one)
  -gt select a 3s range
• Normalize every event -gt Photonflux (Ag1Sic)
• Subtract background from signal (event by event)
• Determine the Energy deposition for the cycles

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Energydeposition in the crystal
average of the central region of the distribution
Central region 13.5 of max.
(2676_1)
ns,nb - of Signal/Background events in the
histogram FWHM - full width at half max. of the
distribution
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Proposed method

• Determine asymmetries from ajacent cycle pairs
• Cut on the beam current (both cycles as one)
  -gt select a 3s range
• Normalize every event -gt Photonflux (Ag1Sic)
• Subtract background from signal (event by event)
• Determine the Energy deposition for the cycles
• Calculate the average asymmetry from the
  cycle-pair-asymmetries

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Asymmetries Ai
histogram of the single asymmetries weighted with
their errros
A gaussian fit to this histogram gives
the average asymmetry
(Fit range 3s, determined from a previous fit
over the full range)
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Result
In comparison to the Tel Aviv Analysis
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Compare to linear fit method
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(No Transcript)
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And compared to prev. analysis
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Comparison Spring - Fall
Results are stable within the errors
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Status now