Analysis Overview

1
Analysis Overview

• Kent Paschke
• HAPPEX Collaboration Meeting
• February 24, 2006

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February 24 April 21
Sunday Monday Tuesday Wed Thursday Friday Saturday
24 TODAY 25
26 27 28 1 2 3 Analysis I 4
5 6 7 8 9 10 Analysis II 11
12 13 14 15 16 17 Analysis III 18
19 20 21 22 23 24 Analysis IV 25
26 27 28 29 30 31 Analysis V 1
2 3 4 5 6 7 Analysis VI COLLAB MEETING 8 COLLAB MEETING
9 10 11 12 13 14 15
16 17 18 19JLAB Seminar? 20 21 22
23 APS Talk 24 25 26 27 28 29
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Technical Notes

• Technical Notes Draft date
• Optics/Q2 Tim, Rob, Bob (Bryan, UMass) ?
• Finite acceptance Bryan, David L., Kent ?
• Backgrounds Ryan, Kent, Bryan, Bob ?
• Asymmetry analysis Lisa, Rich, Hachemi, KK
  ?
• Polarimetry David L., Paul S., Hachemi ?
• Transverse Asymmetry Lisa, Kent ?
• Beam asymmetries
• Cavity performance

• Publications
• 2005 Hydrogen Helium measurement Letter

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Raw Asymmetry Analysis

• Near-term
• - epics words added to run .db files, re-run
  data, slug-pair and run-summary root files (Lisa)
  I
• - Inclusive RUNLIST check review of runs in data
  set to verify runlist/run cuts. (Lisa) I
• Medium-term
• Dither Quality Control (Syracuse) -I
• Review of averaged dither slopes, verifying
  consistency, avoiding outliers, etc.
• There have been almost NO quality checks
  for dither slope calculation/averaging.
• Averaging (Lisa and Syracuse) - II
• -modify run macro to avoid "binning" errors in
  averages
• - macros to average asymmetries by run, slug.
• - macros to average weighted pos difs and Aq.
• - pedestal error over run
• Pedestals/Linearity (Lisa) - III
• - Evaluate possible pedestal errors over run.
• - Verify pedestals at each current scan
• - Verify pedestals used for run periods.
• He Slugs 39-41. Fix these. (UMass) -II
• Exclusive RUNLIST check Ryan

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Raw Asymmetry Analysis

• Longer-term
• Beam Correction Quality (Umass) -V
• - Check systematics for large asymmetry runs
• - Characterize difference between regression and
  dithering
• - Estimate uncertainty in dithering/regression
  corrections.
• This is very important for helium.
• Final Data Set (Umass and Syracuse) - V
• - Make Final run root files with final cuts,
  pedestals, slope averages,
• pair and run sum. files
• - Verify pedestals, cuts, double differences,
  asymmetry corrections for
• final data set.
• - perform final averaging, with various summary
  tables similar to last year.
• - Evaluate asymmetry systematic error (pedestal,
  beam corrections,
• Aq correction).

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Backgrounds

• Helium QE is almost done!
• Check stability over many measurements - I

• Rescattering significant work remains -III
• Aluminum to be removed from rescattering
  probability II
• Det pedestals for very low rates (if necessary)
  -II
• Correct rescattering for convolution with
  inelastic spectrum. -II
• Subtract radiative tail from inelastic spectrum
• - Requires simulation, but doesnt need to be
  precise. (BRYAN) - II

• Aluminum easy, but important cross checks must
  be done -III
• Verify on-line results, mainly trigger quality
  in counting and pedestals in integrating mode
• Verify observed Al dummy targets consistent with
  He/H cryo target spectra
• Reduced density target runs to verify xT
  factor - V

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Backgrounds

• Poletip not yet started
• Propagate through field map to measure
  fraction of pole-tip intersections (Bob) - II
• Estimate possible number of near-tangent
  pole-tip intersections via SNAKE/gener_cone
  (Bryan, Kent)
• check sensitivity to details of collimation
• Tech Note!

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Q2

• Much like last year, and much already done.
  Addendum note to last years tech-note is called
  for.
• Optics issues related to limited sieve
  collimator coverage?
• additional cross-checks of matrix elements vs.
  fp parameters... where does the matrix fail... or
  eliminate holes and re-fit optics db to check for
  errors. - I
• But NO CLEAR ERROR SIGNAL REMAINS... is there
  really anything here to worry about?
• Cross-check (Rob) - III
• Stability/Drift issues. (defer, but think about
  this)
• weight asymmetry average by (changing) Q2?
• Was this stable during hydrogen (Bob, - II)
• Profile Scanner.
• Compare distribution parameters for drift over
  time
• Track Q2 measurement vs. profile parameters over
  time
• Compare profile moments from scanner vs.
  spectrometer Bob, on spectrometer I. UMass,
  on scanner, - II.
• Simulation, reproduce Q2 distribution?

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Simulation

• gener_cone SNAKE
• Reproduce Q2 distribution (update in I)
• Radiative tail for subtraction in rescattering
  background calculation - II
• Average ANS over acceptance, radiative
  corrections (Tech Note) -V
• Average analyzing power over acceptance?
  (probably negligible)
• Estimate possible number of near-tangent pole-tip
  intersections via SNAKE/gener_cone (Bryan, Kent)
  - III
• check sensitivity to details of collimation
• MUCH additional work which may not be needed for
  unblinding
• Improve match to magnetic transport, use optics
  db to reconstruct sieve pattern. Do we have
  comparable data without the septum (for future)?
• improve Multiple Scattering
• Match low density runs.... although what this
  takes isnt clear

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Polarimetery

• Electron Detector re-analysis
• straight-forward, but requires some labor?
• waiting for the photon analysis method to be
  refined, to spin both photon and electron
  analysis together
• We need David L to oversee this analysis
• Photon response function -gt analyzing power. A
  better fit should reduce analyzing power
  systematic uncertainty.
• 2 weeks before automated procedure for response
  function fit
• Compton co-incidence measurement?
• We need to have polarimetery top agenda at next
  meeting. How stable is the polarimetry analysis
  now? What is needed to finish it, at a minimal
  level? - I
• Mott results (vertical component most important)
  - II (for Helium syst)
• Moller results smaller error bar? (how about
  vertical pol error bar?)
• Tech Note

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Transverse Asymmetry

• Goal to complete soon after unblinding.
• Verify background asymmetry ranges
• Verify pedestals, beam corrections. Use
  precision estimates from longitudinal runs for
  correction precision estimates
• Polarimetery verify precision of Moller, come
  up with a defendable precision estimate
• WEEK IV L/R correction factor for He. (kent)
• Tech note...

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2005 - Physics Asymmetry
Helium
2004
APV s 0.21 ppm (3.5)
APV s 0.84 ppm (11.2)
GEs s 0.014
GEs s 0.042
Hydrogen
2004
APV s 0.24 ppm (17)
APV s 0.12 ppm (8)
GEs0.080GMs s 0.025
GEs0.084GMs s 0.012
NOTE Statistical error only!
Systematic error will likely increase Helium
error bar by lt30, and Hydrogen by lt20
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Getting the story out future talks

• JLab Seminar - April 21, 2006?
• First (JLab) release of 2005 results - ltname?gt
• APS _at_ Dallas - April 22-25, 2006 - April
• First public release of 2005 results - Paul
  Souder
• (session chaired by KK)
• PAVI _at_ Milos - May 16-20, 2006
• HAPPEX 2005 results David Armstrong
• Control of Beam Asymmetries- Kent P
• Transverse Asymmetry Lisa K
• Q2 and Backgrounds Bryan M
• CIPANP _at_ Rio Mar - May30-June 3, 2006
• HAPPEX 2005 results Krishna Kumar

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PREx Preparations Meeting Feb 25, 2006
A110, CEBAF Center 900 - 930 Paul Task
List / Warm Septum 930 - 1000 Bob New
Electronics 1000 - 1030 David Compton
Upgrade 1030 - 1100 KK Detector Design
1100 - 1130 Eugene High-Field Moller 1130 -
1200 Discussion of other tasks