[d2n-analysis-talk] Spike at E/p=0 [SOLVED, but begs a new question]

[David Flay]

On Thu, Dec 16, 2010 at 11:18 AM, Brad Sawatzky <brads at jlab.org> wrote:

> There are four ways E/p == 0:
>  1) the code assigns E/p = 0 as a default value,
>  2) the code assigns E/p = 0 as an error/bailout,
>  3) the quantity E really is 0, and/or
>  4) the quantity p is huge (ie. kBig).
>
>
> We need to know which of these cases is contributing to the non-physical
> E/p==0 number, and whether or not that makes sense.  If some are due to
> trigger or hardware problems, then we need to make sure our efficiency
> corrections treat it properly.
>
> The single adc histograms for a single PMT aren't really sufficient
> since the majority of the zeros there just mean that that particular
> cell didn't interact with the particle (which is quite reasonable).
> What I would like to see verified is that the raw sum of the energy in
> the pion rejector layers equals the (summed) pedestal value.  That is,
> I want to verify that getting E=0 out of the "high-level" code really
> means that we had negligible energy deposited in the cells at the lowest
> level.  That would be case '3' in the list.  If that's what is
> happening, then it is strange:
>

Do you mean cutting on L.prl1.e==0 and seeing what shows up in L.prl1.asum_p
(same for prl2)? I don't have a variable for the raw sum.  In which case,
the events at zero for L.prl1.asum_p and L.prl2.asum_p do show up at zero
(blue curve in attached *.pdf).

My cuts are again listed in the titles, if you zoom in.   I'll also have
this plot in the meeting.





-- 
-----------------------------------------------------------
David Flay
Physics Department
Temple University
Philadelphia, PA 19122

office: Barton Hall, BA319
phone: (215) 204-1331

e-mail: flay at jlab.org
           flay at temple.edu

website: http://www.jlab.org/~flay <http://www.jlab.org/%7Eflay>
             http://quarks.temple.edu
-----------------------------------------------------------
-------------- next part --------------
An HTML attachment was scrubbed...
URL: https://mailman.jlab.org/pipermail/d2n-analysis-talk/attachments/20101216/7bfdd6e4/attachment-0001.html 
-------------- next part --------------
A non-text attachment was scrubbed...
Name: prl_E_P_check_20676_12_16_10.pdf
Type: application/pdf
Size: 30976 bytes
Desc: not available
Url : https://mailman.jlab.org/pipermail/d2n-analysis-talk/attachments/20101216/7bfdd6e4/attachment-0001.pdf