On Fri, Mar 5, 2010 at 11:04 AM, Brad Sawatzky <<a href="mailto:brads@jlab.org">brads@jlab.org</a>> wrote:<br><div class="gmail_quote"><blockquote class="gmail_quote">
Vince pointed out the answer. Your cuts are working correctly -- the<br>
second band are cosmics going through the stack 'backwards'. Note that<br>
for good electrons (bulk of the data) t_2m-t_s1=6ns, but for the second<br>
band: t_2m-t_s1=-6ns. At high p0 we have so few electrons that cosmics<br>
actually compete. Interesting.<br></blockquote><div><br>Hmm, that is interesting.. So, I would need a cut on beta > 0 to make this plot look normal again? I'll try it out..<br><br>regarding the S1 timewalk -- I plot left TDC vs. 1/sqrt(left ADC) and I get a straight line (using my corrected values -- to check them.) (based on Chiranjib's approach in the transversity ELOG) <br>
<br>This is good. -- if I <do not> have a cut beta > 0, I see a similar double band structure (separated by about the same time as seen in the avg. time plot) in this plot.<br><br>These plots have beta > 0. L = left PMT, R = right PMT; run 20675 => p = 0.60 GeV, 4-pass. run 20207 => p = 1.70 GeV, 5-pass. <br>
<br>I'll check on S2m as well.<br></div></div><br><br><br>-----------------------------------------------------------<br>David Flay<br>Physics Department<br>Temple University<br>Philadelphia, PA 19122 <br><br>office: Barton Hall, BA319<br>
phone: (215) 204-1331<br><br>e-mail: <a href="mailto:flay@jlab.org">flay@jlab.org</a> <br> <a href="mailto:flay@temple.edu">flay@temple.edu</a><br><br>website: <a href="http://www.jlab.org/~flay">http://www.jlab.org/~flay</a><br>
<a href="http://quarks.temple.edu">http://quarks.temple.edu</a><br>-----------------------------------------------------------<br><br><br>