<br><br><div class="gmail_quote">On Tue, Jul 13, 2010 at 2:06 PM, Brad Sawatzky <<a href="mailto:brads@jlab.org">brads@jlab.org</a>> wrote:<br><blockquote class="gmail_quote">
The 'eff' value for T4 doesn't really mean much. (It isn't really an<br>
efficiency by any standard definition -- I wouldn't worry about it.)<br>
<br>
Now that I think about it a bit more (and I'm suspicious that the<br>
efficiency seems too good to be real), I forgot a some factors in the<br>
expression I gave you. The trigger counts really ought to be multiplied<br>
by the prescale factors<br>
eff_3 = bit3*ps1/(bit3*ps1 + bit4*ps4)<br>
<br>
You'll need to grab the prescales from the ROOT file on every run since<br>
they can change, of course.<br></blockquote><div><br>Wouldn't including the prescales give the latch pattern variable -- LTN = ps*bitN? Since bitN is after the prescale. <br><br>I know that we're missing events in that despite ps = 1 for T3 and T4 for run 20676 (from the <a href="http://www.jlab.org/%7Eadaq/halog/html/0903_archive/090314032236.html">logbook</a>): the LT3 doesn't match bit3 (and more noticeable is the discrepancy of the T4 values) : <br>
<br>Trigger 3 [Bit]: 13870<br>Trigger 4 [Bit]: 10<br>Trigger 3 [Latch]: 13885<br>Trigger 4 [Latch]: 314<br>T3 Trigger Efficiency [using bit variables]:<br>Trigger 3: 99.9280 +/- 0.0228%<br><br>(where I count the number of entries in the histos for 'DL.bit3', etc.)<br>
<br>cuts used (applied to all histos):<br>
<br>
//one track from the target<br>
cut0 = Form("(L.tr.n==1)");<br>
//cut out the pulser, require either a T3 or a T4 trigger<br>
cut0 +=
Form("&&(DL.edtpl==0)&&(((DL.evtypebits&(1<<3))==(1<<3))||((DL.evtypebits&(1<<4))==(1<<4)))");<br>
<br>
cut1 = cut0;<br>
//VDC cuts -- requirement of one track reconstruction<br>
cut1 += Form("&&(L.vdc.u1.nclust==1)&&(L.vdc.v1.nclust==1)");<br>
cut1 += Form("&&(L.vdc.u2.nclust==1)&&(L.vdc.v2.nclust==1)");<br>
<br>
cut2 = cut1;<br>
//PID cuts<br>
cut2 += Form("&&(L.cer.asum_c>300)&&(prl_E_P>0.54)&&(L.prl1.e>200)");<br></div></div><br>PS -- should Cherenkov TDC cuts be used here? I tried it out, and I get eff_T3 ~ 99.96%, as compared to above, at 99.92%. <br>
I tacked on the TDC cuts since I do use them to define good electrons in the Cherenkov. <br><br> Also -- I was looking at Patricia's work on the trigger efficiency -- her left arm results are comparable to mine (99.98%): <a href="http://hallaweb.jlab.org/experiment/E01-012/reports/trig_vdc.pdf">http://hallaweb.jlab.org/experiment/E01-012/reports/trig_vdc.pdf</a><br>
However, she is fairly brief on her description of the calculation. <br clear="all"><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>
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