[Hps-analysis] meeting TODAY

Sho Uemura meeg at slac.stanford.edu
Fri Jun 10 11:42:07 EDT 2016

Yes, that will be a useful number to have for the analysis. It's going to 
be pretty small - from the plots I posted you can see that it will be at 
most 3-4% at low esum, less at high esum (since the out-of-time histogram 
covers 3 bands of accidentals, plus a lot of leakage from in-time).

Should expect this fraction to go down with any additional trident cuts 
(these histos are made with pretty minimal cuts).

On Fri, 10 Jun 2016, Stepan Stepanyan wrote:

> Dear all,
> I may not be able to be at the meeting, so I want to send some comments on 
> accidentals in Esum,
> 3 figures that are posted on the meeting page.
> Clearly it is important to select true coincidences with the cut |dt|<1 ns. 
> But even after that cut there
> will be accidental pairs left, tiny number, but still. In order to estimate 
> the number of accidental pairs
> in the selected events, one simply should count number of events in one of 
> peaks at wrong beam buckets.
> I clearly can see bands on +/- 4 ns, peaks at +/- 2 ns are not clearly seen 
> because of overlap with tails
> of the main peak at 0. So, using peak on +/- 4 ns one can estimate how many 
> accidentals are left in
> |dt|<1 ns cut (if statistics is not good in one accidental peak, one can fold 
> in many together).
> Stepan
> On 6/10/16 7:21 AM, Nathan Baltzell wrote:
>> Hi Everyone,
>> We will have our weekly meeting TODAY at 11:00 (jlab time).
>> Here's a preliminary agenda:
>> https://confluence.slac.stanford.edu/display/hpsg/June+10%2C+2016+DAWG+Meeting
>> Bluejeans connection:
>> https://bluejeans.com/722990411
>> - Matt & Nathan
>> _______________________________________________
>> Hps-analysis mailing list
>> Hps-analysis at jlab.org
>> https://mailman.jlab.org/mailman/listinfo/hps-analysis
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