[d2n-analysis-talk] BB cer pion rejection plots

[Brad Sawatzky]

The change in pion rejection for PMTs 14,16 are pretty strange.  Any
idea why?  I presume the large error bars are due to using T1 or T6
data?  (Which is fine, I'm just checking.)

-- Brad

On Mon, 06 Dec 2010, posik at jlab.org wrote:

>   So I added some error bars to the BB cerenkov pion rejection factors
> that I showed last week. I also redid the rejection factor vs BB Cer
> photo electron cut using the pion selection of E/p<0.8 and 10 <
> preshower < 250.
> 
> So the plot pion_selection.eps shows my pion sample selection.
> 
> I then looked at how many particles from the pion sample were passing
> through the geometrical location of a Cerenkov mirror, I called this
> variable N_p. I then how many of the N_p particles also fired the Cerenkov
> ADC and TDC and called this number of events N_e. I then defined my pion
> rejection factor as
> 
> pion_rejection = N_p/N_e, and following Dr. Meziani's advice took the
> Sqrt(N_p) as my error.
> 
> I did this for each pmt, see cer_pi_rej.eps for the small angle side and
> rhrs_cer_pi_rej.eps for the large angle side. The different data markers
> represent the rejection factor at different BB Cerenkov ADC photo-electron
> cuts. I also plotted the average rejection factor for each side of the
> Cerenkov as a function of photo-electron cut, see cer_avg_pi_rej.eps and
> rhrs_cer_avg_pi_rej.eps.
> 
> I am now going to do a similar thing for the electron efficiency.Please
> let me know what you think of these plots.

-- 
Brad Sawatzky, PhD <brads at jlab.org>  -<>-  Jefferson Lab / Hall C / C111
Ph: 757-269-5947  -<>-  Fax: 757-269-5235  -<>- Pager: brads-page at jlab.org
The most exciting phrase to hear in science, the one that heralds new
  discoveries, is not "Eureka!" but "That's funny..."   -- Isaac Asimov