<br><br><div class="gmail_quote">On Mon, Oct 24, 2011 at 12:19 PM, Brad Sawatzky <<a href="mailto:brads@jlab.org">brads@jlab.org</a>> wrote:<br><blockquote class="gmail_quote">
<br>
On Sun, 23 Oct 2011, <a href="mailto:posik@jlab.org">posik@jlab.org</a> wrote:<br>
<br>
[ . . . ]<br>
<div class="im">> I then computed the ratio of inelastic to misc events for 4 runs, and then<br>
> computed the weighted ratio over the 4 runs. I ended up with the ratio of<br>
><br>
> inelastic/misc events = 3.932 +/- 0.065 %<br>
><br>
> Finally, I also took a look at how the misc. events compare to the<br>
> inelastic events in the BigBite Cerenkov ADCs. This can be seen in the<br>
> plot Neg_Ration_CerADC.pdf, where I plotted the inelastic events in red<br>
> and misc events in blue for several ADCs. On the left are ADCs<br>
> 4(top),5(middle) and 6(bottom). On the right are ADCs 14(top), 15(middle)<br>
> and 16(bottom). Looking at the Cerenkov ADCs, we can see that the misc<br>
> events fall right around the mean value of the inelastic events.<br>
<br></div></blockquote><div>I just want to correct myself again. I had a typo in my original email. I originally said the the ratio of inelastic/misc events was 3.9%, However I meant to say the ratio of misc/inelastic events is 3.9%<br>
<br></div><blockquote class="gmail_quote"><div class="im">
</div>When I look at the CerADC plots I see the ratio of<br>
"inelastic w/ cherenkov signal" : "misc events w/ cherenkov signal"<br>
seems to be 40:1 vs. the 3.9:1 ratio seen in the shower.<br>
<br>
Is there a missing prescale factor or something, or does that tell us<br>
that something like 90% of the misc events are missing signal in the<br>
Cherenkov ADC?</blockquote><div> <br>When computing the ratio of misc/inelastic events, I would need to correct for charge,pre-scale and livetime. However, I computed a ratio for each run, and then computed the weighted average of all the ratios from each run. By doing this the pre-scale,livetime and charge corrections cancel out. When I showed the plots of some Cerenkov ADCs, I simply added all the events from the 4 runs together using <br>
<br>chain->AddFile(run 1)<br> chain->AddFile( run 2)... ect<br><br>So in this way I did not correct for live time, charge or prescale factors. However I did recalculate the ratio correcting for charge, livetime and prescale, and the ratio still was 3.9%.<br>
<br> When I did the ratio seen in the shower, I applied the cut that said if the event triggered any of the 20 TDCs in the correct timing range and the event also passed through the location correlated with the Cer TDC (Cer mirror cut) that fired then it is a good event. So the cut looks something like<br>
<br> (TDC01 && Mir01) | | (TDC02 && Mir02) | | ...(TDC20 && Mir20).<br><br> When plotting the Cerenkov ADCs, I used a slightly different cut. In those plots I showed rather than using the cut that allows any of the TDCs to fire, I used the cut that allows the event to pass only if the event fires the TDC and passes through the mirror location of the pmt I am looking at. So for example when I plotted ADC 04 I had the Cer cut<br>
TDC04 && Mir04<br> And when I plotted ADC 14 I used the cut<br> TDC14 && Mir14 <br><br>In the Cerenkov ADC plots, I only showed 6 of the 20 ADCs that we have. Looking at where the misc. events land in the shower, I would imagine that the misc signals in ADCs 1,2,11 and 12 would be larger, then the ADCs near the physical bottom of the detector. I will take a look at this later today. <br>
<br>So when looking at misc/inelastic in the shower the ratio is 3.9% and when looking at the Cerenkov signal of misc/inelastic which is 1/40 = 2.5%, they do not seem too far apart.<br><br></div><blockquote class="gmail_quote">
You mention that production cuts are in place for these<br>
plots (with the noted exceptions). I presume the Cherenkov ADC/TDC cuts<br>
must also be disabled since I don't see evidence of the cut in the Cer<br>
ADC spectra? (Or is the cherenkov _sum_ still always over 400ch and<br>
these plots are just showing ~1 pe backgrounds?)<br></blockquote><div><br>I have applied cuts to the Cerenkov TDCs and matched the track to the position of the Cerenkov mirrors. There are no Cerenkov ADC cuts applied. The Cerenkov TDC and mirror cuts get rid of most of the 1 pe background which would fall near ADC ch 50 or so. I have attached a plot where I plot the ADCs with same cut I described in the first email, but for the misc events(blue histo.) I have removed the TDC and mirror cut so you can see the 1 pe background.<br>
<br>-Matt<br><br> <br></div><div> </div><div><br> </div><div><br> <br></div><blockquote class="gmail_quote">
<br>
-- Brad<br>
<font color="#888888"><br>
--<br>
Brad Sawatzky, PhD <<a href="mailto:brads@jlab.org">brads@jlab.org</a>> -<>- Jefferson Lab / Hall C / C111<br>
Ph: <a href="tel:757-269-5947">757-269-5947</a> -<>- Fax: <a href="tel:757-269-5235">757-269-5235</a> -<>- Pager: <a href="mailto:brads-page@jlab.org">brads-page@jlab.org</a><br>
The most exciting phrase to hear in science, the one that heralds new<br>
discoveries, is not "Eureka!" but "That's funny..." -- Isaac Asimov<br>
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</div></div></blockquote></div><br><br clear="all"><br>-- <br>Matthew Posik<br>Email: <a href="mailto:posik@temple.edu">posik@temple.edu</a><br>Temple University Physics Dept.<br>Office: BA-319<br>Office #: 215-204-1331 <br>
WebSites:<br>Temple:<br><a href="http://quarks.temple.edu/">http://quarks.temple.edu/</a><br>d2n:<br><a href="http://hallaweb.jlab.org/experiment/E06-014/">http://hallaweb.jlab.org/experiment/E06-014/</a><br><br>