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September 10, 2009

Bernd will present : CNI polarization of protons during 500 GeV run

September 3, 2009

Phone bridge number 617 324 7374 , Time 2:00 pm to 3:30 pm, up to 12 connections
Agenda Bernd will present : CNI polarization of protons during 500 GeV run

September 3, 2009

Present: Scott, Justin, Joe, Willie, Jan, Ross, Bernd, Gene, Hal

Minutes

1. result of analysis of SL09b production
   1. Jan (Drupal blog )
      1. presentation of W-algo ver 4.0 using BTOW & TPC, for 1M input events
      2. Run 9 results as of September 1 | Slides
         1. histogram-based dump of selected events
         2. Larger collections of events: di-jets , W-candidates , Z-candidates
         3. Matt's 3 interactive events in skechup or just one view , at Scott's angle
         4. sequential histograms from pass through 1M events (LT=~8/pb)
      3. M-C simulation analysis histograms for Pythia W-events (LT=320/pb) , filtered QCD-events LT=6.3/pb, Z-events LT=4200/pb
   2. Joe
      1. Uber-preliminary result from Joe's algorithm showing W peak and a hint of a Z peak plots
   3. 1. Suggestions: count # of track pointing to cluster; compare ET vs. PT for electron
   4. Joe adopted his algo developed on M-C to work with Run 9 data
   5. * removed BSMD, changed to tower-based center of gravity, relaxed cuts: PT>5 GeV/c, delEta & delPhi<0.5, isoFraction of 0.8
      1. Uber-preliminary result for 1M input events showing W peak and a hint of a Z peak plots
2. Run 9 data publication strategy has been discussed and in general agreed up. Use of BSMD for PRL paper 1 was discussed - it is worth trying. Effici
3. Questions/comments
   1. from former prominent STAR collaborator:
      • Could the Z-candidates be di-jets? cosmic rays? Do you try to do any charge sign discrimination on the electrons (i.e., opposite sign on the 2 sides for "Z-candidates"
   discussion of Run 9 data publication strategy
   1. Questions/comments from former prominent STAR collaborator:
      • Could the Z-candidates be di-jets? cosmic rays? Do you try to do any charge sign discrimination on the electrons (i.e., opposite sign on the 2 sides for "Z-candidates")? Phi distribution does not appear indicative of cosmics.
      • Most importantly, is "Jacobian peak" absent when you look at 200 GeV data with the same algo and cuts?
      • Lots of questions, but this does look really promising, seems to give you NN W candidates NN Z candidates in the barrel region. It's a bit surprising that such a crude isolation cut, with no away-side ET upper threshold or SMD criterion, would suppress jet background so effectively. We always thought we would have to work much harder than this to unveil a signal above background.
   2. Jan: Mike B. just confirmed we could use BFC filter to get rid of not-BHT3 events from pp200 data. This makes another mini-production request of pp200 data a viable option (there is a small issue thou).
   3. Lots of questions, but this does look really promising, seems to give you NN W candidates NN Z candidates in the barrel region. It's a bit surprising that such a crude isolation cut, with no away-side ET upper threshold or SMD criterion, would suppress jet background so effectively. We always thought we would have to work much harder than this to unveil a signal above background.
4. Ross - vernier scan analysis
   1. lots of detail about how I do the fit
   2. showing now a cross section (which Ross knows can't be right)
5. Joe - BTOW relative gains
6. 1. request of pp200 data a viable option (there is a small issue thou).
   2. Joe: estimate TPC tracking efficiency difference for e+ vs. e-
7. Ross - vernier scan analysis
   1. lots of detail about how I do the fit - Ross is looking for explanation why his calculations are off by ~4 orders of magnitude. knows
   2. Comparison of Vernier scan from 2 pp500 runs - background visible in both
   3. Comments/suggestions:
      • post study with eliminated TP affected the most by the beam background
      • post input data from Angelika
      • exercise the code on mock data to verify it reconstructs width correctly
8. Joe - BTOW relative gains, not yet
9. new phone meeting time moved to : Tuesday 5-6 pm new phone meeting time - no conflict :
10. Monday 4-5pm EDT
11. Tuesday 5-6 pm EDT
Friday 10-11 am EDT
12. TPC tracking efficiency at eta~0. How can we address this issue?
    Below is suggestion from Jerome. In short he offers a welcome at BNL.
    • The convoluted hit issue brought during Jan's presentation: Yuri will show Jan how to access/recognize those. It was generally understood that using those in tracking would require
      • a study of effect in real data
      • a response simulator simulating those convoluted hits so embedding would be properly handled (right, it is not handled in embedding not tracking so goes into a reco inefficiency).
      • We welcome Jan coming at BNL and working with Yuri on characterizing the effect on tracking. A month work would bring a pretty good study (still the embedding is questionably achievable within the workload and timeframe)
13. AOB

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