[Clas_cascades] Notes of eg3 meeting Jul 23

[Elton Smith]

Online: Elton, Kijun, Hovanes, Zhiwen, Ralf, Haiyun  <br>
Notes by Elton. <br>

# Announcements: Summer School at MSU was interesting, learning about rare
isotopes and neutrino physics. Lewis away this week.
# Comments on work at USC (Ralf)
#* Making progress on several fronts
#* Lewis is completing analysis with complete error analysis
#* Checking triggered and untriggered regions, better understanding of
gflux, checking possible incomplete corrections by gflux.
#
[http://www.jlab.org/Hall-B/secure/e1-6/parkkj/g11_analysis/report/07062009.html
Normalization check] g11(Kijun)
#* Concer over fluctuations in the extracted cross Delta cross sections in
the g11 data, checked to see fluctuations in gflux corrections could be
causing this
#* Took the ppi+pi- sample, normalized yield using gflux, then smoothed
the normalized yield to obtain new gflux normalizations.
#* This was used for the new cross section calculation and shown to not
affect the main fluctuations in the cross section. The conclusion is that
the fluctuations are not related to the gflux .
# Phi-- (Hovanes)
#* Added a section on trigger corrections to the analysis hote
#* Updated the plot on UL in the analysis note using a 15% normalization
uncertainty. However, we need a more quantitative estimate.
#* The extraction of the Delta++ signal is affected at low energy and at
high energy due to MM resolution and backgrounds. However, the
normalization should be independent of energy, so we will use the
normalization extracted over an energy from approximately 2 to 5 GeV.
Lewis should determine the energy range for validity of the cross section
determination.
#* Kijun will send Hovanes the plot of the ratio of the Delta++ extraction
to the fitted average.

List of items for next meeting:
# Draft note on normalization (Lewis)
# Trigger bits. Histogram K+Lambda yields integrated over all ST counters
shows a flat distribution for the corrected Bit6 rates, but a jump in the
rates for Bit 5. This does not reflect individual ST histograms, so is
likely a bug. Hovanes will investigate.
# Lewis should determine the energy range for validity of the cross
section determination.
# Kijun will send Hovanes the plot of the ratio of the Delta++ extraction
to the fitted average.


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