Hello,<br><br>Please see the attached file for g20 tracking efficiency with Bogdan's suggestions taken account.<br><br>Vahe<br><br><br><div class="gmail_quote">On Fri, May 6, 2011 at 1:25 PM, Bogdan Wojtsekhowski <span dir="ltr"><<a href="mailto:bogdanw@jlab.org" target="_blank">bogdanw@jlab.org</a>></span> wrote:<br>
<blockquote class="gmail_quote" style="margin: 0pt 0pt 0pt 0.8ex; border-left: 1px solid rgb(204, 204, 204); padding-left: 1ex;">Hello Vahe and Ole,<br>
<br>
I would like to suggest to analyze data as follow (probably<br>
it is close what you have done):<br>
1) Use only strips which are geometrically inside the boundary of<br>
initial kinematical range (plus 1 strip of each side).<br>
2) Search for the tracks within an initial kinematical range:<br>
+/- 9 cm; +/- 1 mm; +/- 15 mrad and +/- 0.35 mrad<br>
(at least three GEM chambers should have the cluster coordinates<br>
which are belong to a straight line within 0.5 mm)<br>
3) Define a probability of the track reconstruction:<br>
- good event which has at least one reconstructed track.<br>
4) Plot a histogram of the tracks number.<br>
5) Define efficiency of reconstruction when at least one track is<br>
in the narrow range from the ideal track.<br>
Here the narrow range is x = +/- 10 mm; y = +/- 1 mm;<br>
\theta_p^{hor} = +/- 2.4 mrad; \theta_p^{ver} = +/- 1 mrad<br>
5) probability of contamination when at least two tracks<br>
are within a narrow range.<br>
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<br>
--<br>
Bogdan Wojtsekhowski<br>
TJNAF, 757-269-7191<br>
<br>
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