[d2n-analysis-talk] BB H2 tracks

[Brad Sawatzky]

On Fri, 07 May 2010, posik at jlab.org wrote:

[ . . . ]
>     First I plotted the z-vertex with no cuts (left) and then the z-vertex
> with the proton cut (right). This is in BB_vz.png
> 
>     Next I looked at the LHRS proton tracks (far right plot). Then seen
> how many show up in the Bigbite (far left plot) and then how many of
> these show up with a z vertex cut "abs(BB.tr.vz[0])<0.2" (center
> plot). This can be seen in BB_vz_track.png. Using this target cut
> there are about 7% of events lost, mostly 0 tracks (ie no track

I think the 7% must be all 0-track events(?)  From the BB_vz_cut plot
you show, 100% of the plotted data fall within the abs(BB.tr.vz[0])<0.2
cut.

> events). This is also consistent with when I made a proton cut + BB 1
> track cut and found about 92% of the good proton LHRS tracks were left
> in the BB.

Good.

> If I plot the events in the bigbite using the proton cut + vz cut + 1
> track cut and compare to the events left after a proton cut + 1 track cut.
> I find less than 1% of events are lost with the target cut.

Hmm.  I am guessing that the 1% of events are really 2+ track events in
BigBite -- is that correct?  Ahh, yes, that's what is shown in your
second BB_vz_track.png figure.  Good.

Now, for those good electron events in BigBite:
  - where do they hit in the BB calorimiter,
  - which Cerenkov mirror do they intersect,
  - what does the Cerenkov adc spectrum look like?

-- Brad

-- 
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
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  discoveries, is not "Eureka!" but "That's funny..."   -- Isaac Asimov