[BLAST_ANAWARE] Minutes of the Blast analysis meeting

From: Michael Kohl (kohlm@mit.edu)
Date: Wed Jun 02 2004 - 12:23:02 EDT


No specific topic, we are going around the people being present.

- NM:
  +update on inclusive D(e,e')
   60 cm runs 71??-77??
   plots yields/asymmetries vs. w-Q2/2m
   comparison with MC
   applies show_deepn_asym....C sees discrepancies, looks into it.

- PK:
  +Working on online monitoring of tdc offsets, pedstals, etc.
  +Uses TGraph for datbase monitor GUI, discusses "update" feature of the
   GUI, whenever there is a new, latest database entry.
  +Monitors expected to be ready next week.

- VZ:
  +Generates neutron timing constants from cosmics analysis
  +Resolution of photon peak presently at 5-7ns FWHM (~13%)
  +lower limit of 5% resolution due to detector thickness of L20 (20cm)
  +MC changes: holding field map for 45 degree angle implemented, works with
   white generator only, rescaling of longitudinal component planned

- AM:
  +shows first 60cm MC for deuterium compared with Arenhoevel theory
   gross behavior looks fine
  +background/empty target:
   background between 40cm/60cm cell has rised
   electronics.map issues should not be the case for empty target analysis
   new empty target data not yet analyzed
   VZ interested in background versus Q2. Background asymmetry?

- TA:
  +continued full tracking on line segments, not complete, ongoing

- CC:
  +Progress on wire chamber calibration, inter-connecting cells.
   Wants to give talk next time
  +Requests a (grad) student to perform fitting work (Eugene?) or an
   undergrad.
  +Has an explanation for jump in resolution as function of phi (at certain
   phi cells drifting apart of each other)

- DH:
  +gives lecture on attempt to parameterize swimming of tracks
  +mid-point of a track in each superlayer best defined (115mu) compared to
   the other two (200mu)
  +gets x1-x6 for three superlayers (2 x's each)
   
  +parameterize P,theta,phi,z (x_i) with polynomial
  +generates MC e': P 50MeV-1GeV, theta 5deg-100deg, phi -17.5-17.5 ,
   z -500-500
  +propagate events into Wch
  +resolve for polynom parameters
  +CUBCUB lazy-6th order solution (reduced matrix)
  +200mu assuming 200mu in x_i resolution
  +obtained resolutions:
           LIN QUAD CUB BLASTMC CUBCUB +200mu
   p/MeV 160 87 67 30 8 30
   h/mr 32 12 5 8 0.6 4.8
   f/mr 15 3 2 12 0.4 2.3
   z/mm 24 9 3.5 10 0.5 4.5

  +obtained momentum resolution is ~2% on MC data. Needs to apply to real
   data.
  +turn on physics in MC
  +can "train" the algorithm also with real (elastic) data
  +assumes that t2d works correctly
  +Maybe ultimately a replacement for the swimming method. Is FAST! VERY FAST!

- about recrunching
  +separate neutron analysis and Wch resolution needs for recrunch
  +neutron recrunch from dst, need to change "lrd" such that tracking is
   not repeated for electron (or implement option to do so).
  +A whole dataset is then expected to be recrunched within a day (CC)
  +Total (Wch) recrunch from raw also needed before collaboration meeting,
   best peroid during shutdown 6/8-6/22, all buds and spuds available.
  +TB fixed Electronics~???.map's, just specify path in blastrc and use
   electronics.ma from MYSQL
  +CC: Suggested to create tagged cvs versions for lrd/lrn to be used

Regards,

  Michael

-- 

+-------------------------------------+--------------------------+ | Office: | Home: | |-------------------------------------|--------------------------| | Dr. Michael Kohl | Michael Kohl | | Laboratory for Nuclear Science | 5 Ibbetson Street | | MIT-Bates Linear Accelerator Center | Somerville, MA 02143 | | Middleton, MA 01949 | U.S.A. | | U.S.A. | | | - - - - - - - - - - - - | - - - - - - - - -| | Email: kohlm@mit.edu | K.Michael.Kohl@gmx.de | | Work: +1-617-253-9207 | Home: +1-617-629-3147 | | Fax: +1-617-253-9599 | Mobile: +1-978-580-4190 | | http://blast.lns.mit.edu | | +-------------------------------------+--------------------------+



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