Re: pi0 reconstruction

[Alexander Somov <somov@jlab.org>]

Hi Matt,

Thanks a lot for your commments. I think that you
are absolutely right ( we should check/tune calibration).

My main concern is that I might use not the latest
'official' version of the reconstruction, i.e., the
latest version is not in the repository.
( I remember that sometime after the review Richard updated/fixed
the BCAL geometry. There were no hits in the BCAL at all when
I tried to use libs from the repository...)

It would be very nice if someone, who has been using an 'official'
reconstruction, check that his code (geant/reconstruction)
corresponds to that in the svn.

My understanding is that Mihajlo is also using his 'local'
reconstruction (?)

Cheers,
       Sascha


P.S. Later on I definitely could contribute to the calibration
issues.






On Thu, 10 Apr 2008, Matthew Shepherd wrote:

>
> Hi Alexander,
>
> Both the BCAL segmentation and maybe the BCAL response has changed
> since we tuned the BCAL reconstruction and "froze" it some time ago
> for the studies done for the calorimetry review.  One thing that needs
> to be done is to look at the results of the BCAL beam test and make
> sure that our model for the response represents our best possible
> knowledge.  Independent of clustering, I suspect the calibration might
> be off if attention lengths or thresholds have changed.  I'm not
> surprised that you are seeing a discrepancy at this level -- in
> general we need to do a tune-up of the reconstruction code.
>
> -Matt
>
>
> On Apr 10, 2008, at 3:34 PM, Alexander Somov wrote:
> > Hi Mihajlo,
> >
> > I have a quick question:
> >
> > I generate 3 GeV photons using a single
> > track generator
> > c particle  momentum   theta  phi  delta_momentum delta_theta
> > delta_phi
> >  KINE   101    3.0        70.    0.      0.              0.001   360.
> >
> > and obtain a 'strange' BCAL response; the total energy in the
> > event obtained by summing up  DBCALMCResponse entries is
> > shifted by about +150MeV (see plot attached to this mail).
> >
> > Do you know what the problem could be (do I miss smth, it seems that
> > there
> > is no noise simulated here) ?
> >
> > I checked out bcal reconstruction from a repository.
> >
> >
> > Thanks,
> >       Sascha
> >
> >
> > <gamma_3gev_70deg.ps>
>
>