[Halld-pid-upgrade] [Revised Logentry] DIRC Hit Pattern data/MC comparison

[Justin Stevens]

Thanks to Matt for pointing out that I had extra pages in the PDFs.  They should be fixed now to only have one page for each (one for each bar).  

PMT hit time distributions are also now included as PDFs, where you can see how the cut (hit time > 38 ns for reflected photons) may affect the hit pattern distributions on the PMT plane.

-Justin

> On Feb 11, 2019, at 2:14 PM, Shepherd, Matthew <mashephe at indiana.edu> wrote:
> 
> 
> Beautiful!  Congratulations on achieving this very nice milestone!
> 
> 
>> On Feb 11, 2019, at 10:50 AM, jrsteven at jlab.org wrote:
>> 
>> DIRC Hit Pattern data/MC comparison
>> 
>> 	• Edit
>> 	• Delete
>> Lognumber 3650993. Submitted by jrsteven on Mon, 02/11/2019 - 08:40. 
>> Last updated on Mon, 02/11/2019 - 10:45
>> Logbooks:	HDDIRC
>> Attached Files:	
>> <application-pdf.png>Data pixel maps for direct photons (each page is a bar and canvas is an 5 cm step in x)
>> <application-pdf.png>bggen MC pixel maps for direct photons (each page is a bar and canvas is an 5 cm step in x)
>> <application-pdf.png>Data pixel maps for reflected photons (each page is a bar and canvas is an 5 cm step in x)
>> <application-pdf.png>bggen MC pixel maps for reflected photons (each page is a bar and canvas is an 5 cm step in x)
>> To compare the PMT hit patterns between data/MC, we selected pi+ from rho events in both data (runs 60590-60617) and bggen MC. The requirements for the track are that it enters bar #3 (4th from the beamline) at a position 0 < x < 5 cm, and the track momentum > 4 GeV (to have a constant cherenkov angle). This small area allows us to see a unique hit pattern on the PMT plane seen below. The first image is for photons which travel directly to the optical box with data (top) and MC (bottom):
>> 
>> 
>> 
>> The plot below shows photons reflected by the far end of the bars again with data (top) and MC (bottom). These are separated by a time cut:
>> 
>> 
>> 
>> Bottom line: we see clear Cherenkov photon patterns! More investigation is needed to understand the details and study the photon yield per track.
>> 
>> In the attachments you'll find PDF files which have a page for each of the bars and canvases for different x regions of the bar. Separate files are there for data and bggen MC for comparison.
>> 
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>