[Halla_pi0] pi0 meeting summary oct 10 2011

[richard lindgren]

Hello,
Oct 10 pi0 meeting summary,

Khem had nothing new to present.

We discussed with khem his previous result on reconstructing the vertex vz from the data.
The data show that the length of the target is 
a 0.0589413
b 0.0579506
c 0.0573692
d 0.0558614
h 0.0580208
g 0.057441
f 0.0563941
e 0.054819
i 0.0574594
j 0.0558974
k 0.0544701
l 0.0531135

There are two questions. Why doesn't the data show that the target length is 6.0 cm? Why does it fluctuate between 5.3 and 5.9 cm?
Is it because Khems method to determine the centroid of the front and back of the window have a large error on it due to overlap with the hydrogen data Is the target cell actually smaller than 6.0 c?  Lindgren will check to see what the exact dimensions of the cell and windows are?

The results showed that yield from the downstream  window was maybe 20% more than upstream window. We thought the upstream window having a smaller angle would show more yield. Khem's cut on the time was on the accidentals in order to enhance the window over the hydrogen to see
the window more clearly. Maybe one window is thicker than the other.

We asked Khem to repeat the vz but with cut on missing mass to be sure we were not dominated by  crazy events. We also asked him to do the same for the dummy target and compare the two data by overlapping the results for us to see.

Khem is also waiting for some results from the HRS from Nilanga.

Cole has fitted the new Mainz data and has new LET's. He will discuss it another time when more people are at the meeting.

Richard


Dr. Richard A Lindgren
Research Professor of Physics 
Department of Physics
University of Virginia
382 McCormick Rd
Charlottesville, VA 22904
ral5q at virginia.edu







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