[Halld-physics] [Halld-offline] list of reconstruction topics

[Curtis A. Meyer]

Hi Mark -

   that looks like a good list. I might suggest that it be reworked a 
bit. In particular,
we have three broad topics with issues: (1) tracking (2) photon 
reconstruction and
(3) particle identification.

   With regard to (1), the problems manifest themselves as large 
chi-squares from tracking
and the tracking errors being problematic in a way that cannot be 
systematically corrected.
I would guess that these are correlated with underlying issues in:
   i) pattern recognition where incorrect hits are used.
  ii) large scattering in material between CDC and FDC.
iii) possible errors in the fitting procedure itself.
iv) other as yet unknown causes.

    I think that the only way that we are going to make progress here is 
to go systematically
through the code and try to identify problems and fix them. I believe 
that Simon, Paul M. and
possibly Kei after the beam tests.

With regard to (2), my feeling from our b1-pi studies is that this is 
coupled to the BCAL
reconstruction. In this case, the big improvements will hopefully come 
from tuning the
algorithm in the the existing code. However, there are some caveats.
   i) The BCAL readout segmentation will affect this. We need to settle 
this asap, or
       move forward under the 1-2-3-4 assumption.
  ii) Once segmentation is settled, we can go back and tweak the 
parameters in the BCAL
       code.

   In this case, Matt updated code which is checked in and Will L. is 
now looking at it.
Modulo (i) being decided, I hope that we can move forward fairly quickly 
here.

Finally, for (3), this is a higher level issue that will ultimately 
require (1) and (2) to be improved.
Your posed questions put this in the light more of discussion, rather 
than underlying software
issues. While it may lead to issues as we move forward on the above, it 
is hard to say at the
moment.

    For progress, Paul M. is going through the code looking at the 
inputs to the PID and trying
to make sure that they make sense.

My 2cents ..  Curtis
On 8/30/11 3:05 PM, Mark M. Ito wrote:
> Folks,
>
> As discussed at yesterday's Physics meeting, I put together a
> preliminary list of reconstruction topics that we might use to guide
> organization of our work. Some are rather general and could stand
> filling in with sub-topics. And the list is by no means comprehensive.
> Feel free to add/modify topics.
>
> http://www.jlab.org/Hall-D/software/wiki/index.php/Reconstruction_Tasks_and_Topics_for_Further_Development
>
> A couple of notes on using the wiki:
>
> 1. Every wiki page has a discussion page. In this case it might be
> useful for recording reasons for changes or for proposing them.
>
> 2. Every wiki page can be "watched" if you want to be notified of
> changes to the page. Again, perhaps useful in this case.
>
>     -- Mark
>
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-- 
Prof. Curtis A. Meyer		Department of Physics
Phone:	(412) 268-2745		Carnegie Mellon University
Fax:	(412) 681-0648		Pittsburgh PA 15213-3890
cmeyer at ernest.phys.cmu.edu	http://www.curtismeyer.com/