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Analysis Over view

Analysis Over view. Kent Paschke HAPPEX Collaboration Meeting February 24, 2006. February 24 – April 21. Technical Notes. Technical “Notes” Draft date Optics/Q 2 – Tim, Rob, Bob (Bryan, UMass) ? Finite acceptance – Bryan, David L., Kent ?

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Analysis Over view

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  1. Analysis Overview Kent Paschke HAPPEX Collaboration Meeting February 24, 2006

  2. February 24 – April 21

  3. 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

  4. 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 • Detector Weights (UMass) - II • Density Fluctuations, detector correlations (UMass) -IV

  5. 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). • Tech Note! -V

  6. 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 doesn’t 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

  7. 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!

  8. Q2 • Much like last year, and much already done. Addendum note to last year’s 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?

  9. 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 isn’t clear

  10. 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 -> 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

  11. 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...

  12. 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%) GEs+0.080GMs:s ~ 0.025 GEs+0.084GMs: s ~ 0.012 NOTE: Statistical error only! Systematic error will likely increase Helium error bar by <30%, and Hydrogen by <20%

  13. Getting the story out – future talks • JLab Seminar - April 21, 2006? • First (JLab) release of 2005 results - <name?> • APS @ Dallas - April 22-25, 2006 - April • First public release of 2005 results - Paul Souder • (session chaired by KK) • PAVI @ 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 @ Rio Mar - May30-June 3, 2006 • HAPPEX 2005 results – Krishna Kumar

  14. PREx Preparations Meeting Feb 25, 2006 A110, CEBAF Center 9:00 - 9:30 Paul Task List / Warm Septum 9:30 - 10:00 Bob New Electronics 10:00 - 10:30 David Compton Upgrade 10:30 - 11:00 KK Detector Design 11:00 - 11:30 Eugene High-Field Moller 11:30 - 12:00 Discussion of other tasks

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