[d2n-analysis-talk] BB cer cuts

[posik at jlab.org]

Hi all,

  I am implementing my Bigbite Cerenkov cuts to attempt to calibrate the
ps/sh at 4pass beam. I just want to make sure that I am doing the
correct cut. So my code goes like this:

I open a replayed ROOTfile and grab the first event
       T->GetEntry(0);

 I then want to create the Cerenkov cut. First I define two integrers,
adc_flag_cut and tdc_flag_cut and set them to 0. I then loop over all cer
pmts and apply cer mirror and 7 photoelectron cut to the ADC. If any PMT
lies within the mirror cut and has more than 7 photoelectrons,
adc_cut_flag is incremented. So if adc_cut_flag >0 than the adc condition
was met. I also then do a similar thing for the multi-hit TDCs using
tdc_cut_flag. I loop over all PMTs and the number of hits each TDC got
and if the TDC signal falls in the TDC cut window then tdc_cut_flag is
incremented. So if tdc_cut_flag>0 then the TDC condition is satisfied. It
looks something like this:

for(i=0;nevents;i++){
 T->GetEntry(i);
adc_cut_flag=tdc_cut_flag = 0.0

//do this loop for each event
   for(Int_t pmt=0;pmt<20;pmt++){
     if(mir[pmt] && adc_[pmt]>7p.e){adc_cut_flag ++;}
     for(Int_t nhit=0; nhit<tdc_hits[pmt]; nhits++){
         if(tdc[pmt][nhits]<tdc_high && tdc[pmt][nhits]>tdc_low)
         {tdc_cut_flag++;}
      }
     }
 if(adc_cut_flag>0 && tdc_cut_flag > 0){
   cout<<"event "<<i<< " passed cer cut"<<endl;
  }
 } //end event loop

Where tdc_hits[pmt] is just Ndata.DBB.BBcerTxx, xx= pmt number
      tdc_values[pmt][nhit] is the TDC signal value on the PMT for the
nhit hit. So since there are 20 TDCs and each has a max of 16 hits
tdc_values is a double array of [20][16].

Now I can combine the tdc_cut_flag and the adc_cut_flag to form a complete
cerenkov cut that can be applied to each event.

 Does this seem like the correct implementation of the cerenkov cut?
 Note the large photo electron cut is just to make sure I have a cleaner
electron sample for the shower calibration.

Thanks
Matt