[Clas_cascades] Notes: Phone conference Aug 26, 2009

[Elton Smith]

Present: Hovanes, Stepan, Elton, Kijun
On the phone: Ralph, Zhiwen, Lewis, Haiyun <br>
Notes by Elton.


== [[Update 8-26 | Normalization studies]] (Lewis) ==
# Normalization note has been circulated, feedback welcome
#* Kijun has provided suggestions already
# Updates
#* problem runs removed (about 6 or 7)
#* y-projections of trigger corrections plotted. Corrections changed from
1.95 to about 1.87.
#* New comparison of cross sections with g11. Difference between means is
about 20%
#* Kijun: Largest changes is probably due to removal of the low-intensity
runs.
#* There is still a small discontinuity (in the Delta data) between
triggered and untriggered regions. Presently using a factor of 4.54. To
smooth out the data, a factor of 4.7 is needed and this almost eliminates
the differences between the eg3 and g11 data sets.
#* Note that the trigger to untriggered correction is taken from [[Tagger
and UnTrigger Trigger ratio | Lambda analyis]] by Haiyun.
#* Elton: the comparison of eg3 and g11 should be done separately for
triggered and untriggered regions. (Note: Kijun already has some of these
rations, but not yet on the web).
# Analysis if final, except for some final discussions on the
triggered/untriggered correction.

== [[KSigma update August 26 2009 | Tagger timing studies]] (Haiyun) ==
# The lambda yields (see previous) as a function of energy showed
troublesome T-counters 9, 11 and 19
# T-19 is at the boundary of the triggered region.
#* The problem here is that the counter itself seems to be inefficient. It
overlaps with both 18 and 20, with a large overlap with 20. The overlap
region with 20 is not triggered, so many events are lost that should have
been triggered by 19. Some show up as "stolen" hits in 20, but only one in
about 4.5 gets into the data.
# T-9 and 11 seem to have additional "noise" or background.
#* The self-timing peak is not at zero but comes from accidental bunches
which are cut in the data. Assuming these are superflous, the data might
be ok, but the gflux normalization incorrect. Might need to investigate
further for studies of the untagged region.
#* For the Phi analysis, these counters should probably be dropped. These
correspond to T-17, 18 (T9), T21,22 (T11), and T37,38 (T19).

== Next Meeting, Wed Sep 2 ==
# Feedback on normalization note to Lewis
# Lewis produce new, close to final draft, of normalization note
# Hovanes: Phi analysis, drop bad T-counters. Decide on final systematic
errors from normalization
# Elton (and others): give feedback on analysis note.


Elton Smith
Jefferson Lab MS 12H5
12000 Jefferson Ave
Suite # 16
Newport News, VA 23606
elton at jlab.org
(757) 269-7625
(757) 269-6331 fax