[BLAST_ANAWARE] analysis meeting 11/06

From: Tancredi Botto (tancredi@mitlns.mit.edu)
Date: Thu Nov 07 2002 - 11:18:15 EST


please let's have some decent threads on analysis issues. The subject
lines are for the topics below.

Also, if you are lost on shift, start with the blast book. There is
general information there that could be useful also for you.

_ There was again a call for knowing what cuts to use for the CC
  efficiency. Note, CC efficiency is not a project to take home, but
  something we need online to plan the next shifts. See my next email
  The goal is to understand what is the working point of the CC with field
  on, that affects their ADC spectra (cc_eff vs Hv, threshold)

_ L/R at some point we will analyze data with field on. JS has done some
  work with field off using show_protons.C and tuning Cuts.C. But this
 was also done ("by hand") before the collaboration meeting. To really
 make progress on this, we want tdc offsets

_ TDC offsets: peter could not attend but his progress is noticeable.
  Basically the macro works. It "measures" the tof lenght (in tdc
  channels) rather than assuming it. This was a good choice, as indeed the
  Wch cuts into the edges of the tof acceptance. So we don't get data all
  over the tofs. PK, I would cut close to 90% of the mean or the
  "flat" region (not at 50%) to avoid counting particles straggling in.
  I would cut more into the elastic protons (ttl-ttr, ttr-ttl)

  Expect results for end of the week. Needs feedback to other SCrecon
  "handlers".

* Just to clarify the analysis structure. The ADC and TDC offset
  subtraction is done in the reconstruction. So it does not depend on
  ntuples. When TDC's are in we will move to commis/phase3. Note, between
  phase2 and phase3 only the cuts in the macros really change, as they
  assumed offset subtracted data in the ntuples

* Ntuple size: for the "raw" ntuple (all hits retianed) we can only have
  tof's and cc's. The NC will be on a separate raw ntuple. A switch would
  be nice so as to speed up analysis if this is slowed down by the NC
  (when?). There is no problem with the eep ntuple (data reduction)
  Adrian will be testing the NC e-map/ntuple today.

* We will not start using trees,branches during commissioning.
   that's a shut down project.

_ CC has prepared some info on the various options for init.C, how it
  uses Cuts.C.

  Soon there will be a summary of the commis/phaseX analysis structure.
  Ask fellow shift-takers. THat is the best way to get information. You
  don't have to be a root guru to do analysis

-- 
________________________________________________________________________________
Tancredi Botto,  		phone: +1-617-253-9204  mobile: +1-978-490-4124
research scientist		MIT/Bates, 21 Manning Av    Middleton MA, 01949
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