Conclusions from last week's meetings

From: Michael Kohl (kohlm@mit.edu)
Date: Mon Apr 10 2006 - 10:55:22 EDT


Hi,

here are my summarized conclusions from the Analysis meeting last Thursday
2006/04/06 and the Collaboration meeting last Friday 2006/04/07:

Crunching:
-Fix timing+pedestal issues in database, bugfixes (pathlenth and
  missing entries) and tag and recrunch v3_4_19 hydrogen + 2004/5 deuterium

To determine kinematic corrections:
-Fix handling of MASCARAD to simulate realistic radiated ep
-Compare MC with RAD/ELOSS=on and off with realistic resolution and
  parametrize effects on p_e and p_p
-Determine "residual" kinematic offsets for rad/eloss corrected
  variables and parametrize in a suitable way

To use kinematic corrections:
-Resulting kinematic corrections from above are free of rad/eloss
  effects and should be applied as such. It is up to the analyst
  to decide wether the rad/eloss effects shall be accounted for in the
  data reconstruction or in the Montecarlo only. In any case, observed
  yields after applying residual kinematic corrections should resemble
  MC yields with RAD/ELOSS turned on.

Spin angle:
-Define best spin angle profiles th_spin(z) for 32/47 degree data sets
  from Genya's measurements
-Use spin angle map in Montecarlos for each of edel,epel,d(e,e'p)n and
  determine most likely global offset to this given map (by matching
  Pzz,hPz in both sectors for same Q2bin). Result should be a corrected
  map from each above reaction channel, including an error estimate for
  each offset.
-For each reaction edel,epel,d(e,e'p), compare yield-weighted average
  for the three resulting maps from edel,epel,d(e,e'p) and see if they
  agree within the error margin
-Define final map by error-weighted mean. This map will have to be
  used by every analysis MC without modification.

Analyses:
-In general, above updates need to be applied, cuts revised

-d(e,e'p) hPz, AedV, AdT:
  +Agreement of AedV with MC vs. pmiss improved after recrunch
  +hPz still Q2 dependent even with new geometry. Mainly lowest Q2 bin
   higher. Statistics allows to use smaller binning. Do data+MC yields
   match as a function of Q2, and in each Q2bin as function of pmiss?
  +Spin angle map in MC?
  +Variation of extracted hPz with spin angle offset to the map?

-d(e,e'n) GEn:
  +Mismatch data/MC yield at lowest Q2 bin. Such a mismatch could
   potentially explain hPz problem from above
  +Comparisons old/new extraction, highest Q2bin seems to come down

-p(e,e') inclusive:
  +Event selection and backgrounds: trigger type 3 included
  +MC comparisons with Epel+MASCARAD+MAID
  +Other models? S-L, DMT?
  +Mascarad properly combined with Epel? Polrad implementation?

-p(e,e'pi+):
  +Need to define and apply most suitable kinematic correction
  +Resolve yield discrepancy compared to Aki's analysis
  +Verify error bars
  +Implement S-L and DMT models in MC
  +Cross section estimate to verify ballpark
  +pi0 channel

-d(gamma,pn):
  +Event selection, phase space and acceptance, cross section ballpark
   confirmed.
  +Empty-target yield?
  +First extraction of T20 and T22 at theta=90. Opposite sign for T20.
  +Montecarlo?

Regards,

    Michael

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