[Clas12_calcom] DC calibration challenge

[Raffaella De Vita]

Hi Mac,
we can discuss the proposed plan at today CalCom meeting.
On my side I don't have objections on starting from a simpler situation 
based ob preselected tracks as you propose at point 1).  I have already 
setup scripts to launch simulations for such single track events and I'm 
ready to start. I would need to know the phi range and the number of 
events you need.
To practically implement the rest of the plan, we should coordinate with 
Mauri to make sure the planned work is consistent with the 
implementation of the time to distance functions in the gemc hitprocess.
Talk to you later,
     Raffaella

Mac Mestayer wrote:
> Hello Raffaella and Dan;
>
> Our group has made considerable progress on developing a
> calibration suite for the chambers.
>
> For a while, we have had a complete (if untested) functional
> form which describes how the drift time depends upon the track's
> distance from the wire, the local angle of the track and the local
> value of the B-field.  We also built a ROOT-Minuit fitter which
> fit time as a function of DOCA which has been operational for
> many months.
>
> Now, we are making two major changes:
> 1- putting the fitting under a JAVA-based graphical interface, and
> 2- introducing a realistic distance to time function into GEMC.
>
> We are aiming to achieve the CALCOM group's goal of producing
> GEMC data with a distance to time function using a blinded set
> of parameters; reconstructing with our initial set of parameters,
> and running the calib. gui to determine a better set of
> parameters, and iterating until we get back to something close
> to what was put into GEMC.
>
> I propose that we proceed with the following steps:
>
> 1) generate GEMC tracks at a few selected kinematics: 6 GeV/c electrons
> at 20 deg.; 3 GeV/c pi+'s at 15 deg. with distance to time digitization
> done with nominal parameters; followed by reconstruction with
> nominal parameters and running the calib. gui.
>
> 2) Once we can do step 1 with some reliability, we can try the same
> tracks but with GEMC digitization with slightly distorted parameters
> and repeat the steps.
>
> NOTE: steps 1 and 2 do not require any hit selection criteria since
> all tracks are the same (except for random smearing).
>
> 3) Once this converges, we try using a Pythia-generated set of
> tracks.  We then work on developing criteria for the data-selection
> cuts, and then do the fitting, re-cooking, etc.
>
> 4) Finally, we can use Pythia events with a blinded set of input
> distance to time parameters.
>
> Comments? ... or suggestions?        - Mac
>
>
> "mestayer at jlab.org", (757)-269-7252
>