[Eg6_analysis] Checking the performance of the extracted drift speed corrections

[Nathan Baltzell]

Hi Mohammad & EG6,

I am noticing some strange things with this new data.  While the
yields in dz(CLAS-RTPC) peak are increased like your good track
yields, S/B ratio is smaller than it used to be (but maybe that
is ok).  Next, the width of the peak is larger.  So I looked at
dz vs theta, and that same dependence of the peak position in
pass1v1 is now at least 3x larger.   Also, if you look at it as
function of z, things are quite different:  as you move upstream,
dz peak gets washed out, whereas before it was pretty clear at
all vertices.  Do you see the same?  I don't think any of these
effects are coming from the electron vertex, as a quick event-by-
event scan shows the electron vertex is basically unchanged, and
the beam windows haven't moved.

Any ideas?  I put a few of these plots on the wiki:
https://clasweb.jlab.org/rungroups/lowq/wiki/index.php/Gempass1v2nab

It might be useful to see some more plots of the change in
reconstructed quantities for the overlap events.  Like
dz/dtheta/dp versus theta/z (you already showed dp vs z).

And maybe we should go ahead and recook the rest of 1 GeV to
look closer at elastics once 64bit user_ana issues are resolved.

Regards,
Nathan



On Thu, 16 Jan 2014 11:02:16 -0600, <hattawy at ipno.in2p3.fr> wrote:

> Hello Nathan,
>    For the new region which is around 2 rad in phi, it is not totally new
> region. If you see in the previous cooking it exists but not very
> clear.
>
>    About the 60% increase in the 1.2 GeV, yes the TDCmax and the drift
> speed they are consistent in the two method with a variation of 1%. It
> is not clear for me why we have this increase. It might be the fact
> that we compared the drift speed of the golden elastic events to the
> one of good tracks. If you can have a look at the two versions of
> cooking for 1.2 runs, you will see the distributions of sdist, edist
> and the other parameters getting narrower in the new cooking, while
> they have been wide before and large number of the tracks they were not
> included in the initial drift speed comparison.
>    The new cooked files are in:
> /volatile/clas/claseg6/gempass1_v2/6gev/
> /volatile/clas/claseg6/gempass1_v2/1p2gev/
>
>    The old cooking are in:
> /volatile/clas/claseg6/gempass1_v1/6gev/
> /volatile/clas/claseg6/gempass1_v1/1p2gev/
>
> Best regards,
> Mohammad.
>
>
>
>> Hi Mohammad,
>>
>> Looks like you also picked up a region of phi that didn't even exist
>> before (~2.2 rad)!
>>
>> Is it correct that there is 60% increase even in the 1.2 GeV runs that
>> were being used
>> for the previous calibrations?  I thought old and new drift speed were
>> consistent there?
>>
>> And can you tell me where these newly cooked 10 runs are?
>>
>> Regards,
>> Nathan
>>
>>
>>
>> On Thu, 16 Jan 2014 09:57:42 -0600, Mohammad Hattawy
>> <mohammad.hattawy at gmail.com> wrote:
>>
>>> Dear all, As we have seen from the previous studies, the drift speed is
>>> changing during the experiment. I have been working on correcting the
>>> drift speed. New correcting >parameters are extracted and implemented  
>>> in
>>> the cooking package. Selected 10 test runs were recooked with these new
>>> modifications.
>>> I did a study of the performance of these corrections. As a result, we
>>> collect more good tracks in the RTPC. This incease is ranging from 60%
>>> to 126%.  A detailed >study can been found here:
>>> https://clasweb.jlab.org/rungroups/lowq/wiki/index.php/Drift_Speed_Correction:_Results
>>>
>>>  Comments and suggestions are greatly appreciated.
>>>
>>> --Best regards,
>>> Mohammad Hattawy._______________________________________________
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