sPHENIX discussion of software

[hachiya <hachiya AT rcf.rhic.bnl.gov>]

Hi Tony,

INTT team knew that problem.

We should use the following values in G4_TrkrVariables.C
  double offsetphi[4] = {0.5 * 360.0 / nladder[0], 0.0, 0.5 * 360.0 / 
nladder[2], 0.0};

instead of the current value below:
  double offsetphi[4] = {0.0, 0.5 * 360.0 / nladder[1], 0.0, 0.5 * 360.0 
/ nladder[3]};


This can solve the half ladder shift problem.

Best regards,

Takashi

2023-10-07 13:00 に Anthony Frawley via sPHENIX-software-l さんは書きました:
> Hello,
>
> Joseph Bertaux has done a nice job of putting together local to global
> transforms for the INTT based on the survey data. He and I have been
> working together on getting the survey alignment parameters in a form
> that we can use in offline.
>
> But when we compared the transforms from the survey to the transforms
> used in simulation, we found that the phi positions of the ladders in
> simulation are different by half of a ladder spacing relative to the
> actual detector. We identified how this happens on the software side:
>
> In coresoftware, the default ladder phi offsets are correct:
> https://github.com/sPHENIX-Collaboration/coresoftware/blob/0d893f314c83936bdcd5ced628997992d80fa946/simulation/g4simulation/g4intt/PHG4InttSubsystem.cc#L191
> [1]
> (notice the nonzero offsets are for layers 3 and 5)
>
> However the values in G4_TrkrVariables.C are incorrect, and they
> override the correct values from PHG4InttSubsystem.cc:
> https://github.com/sPHENIX-Collaboration/macros/blob/7d8c9b53784694a9b95c2200cb2db19c6745494e/common/G4_TrkrVariables.C#L80C5-L80C5
> [2]
> (notice the nonzero offsets are for layers 4 and 6)
>
>  This does not cause problems when analyzing simulated data, since the
> offline code uses the same G4 geometry as the simulation does. However
> it does mean that:
>  1)  We will have to change the G4 geometry before we analyze real
> data, because the offline code currently thinks the INTT ladders are
> not where they really are.
>  2) Fixing the INTT geometry will break analyzing the existing
> simulations.
>
>  We should discuss how to deal with this at the next software meeting.
>
>  Tony
>
>
>
> Links:
> ------
> [1] 
> https://urldefense.com/v3/__https://github.com/sPHENIX-Collaboration/coresoftware/blob/0d893f314c83936bdcd5ced628997992d80fa946/simulation/g4simulation/g4intt/PHG4InttSubsystem.cc*L191__;Iw!!PhOWcWs!3aJV9eZ5lloVigNF9KnvWaPcES2huppA5JOPJqhu8S2k27pPhM7T_EaRxVZP-OBm_MCUyyD7y5T-KvriLx0$
> [2] 
> https://urldefense.com/v3/__https://github.com/sPHENIX-Collaboration/macros/blob/7d8c9b53784694a9b95c2200cb2db19c6745494e/common/G4_TrkrVariables.C*L80C5-L80C5__;Iw!!PhOWcWs!3aJV9eZ5lloVigNF9KnvWaPcES2huppA5JOPJqhu8S2k27pPhM7T_EaRxVZP-OBm_MCUyyD7y5T-AtKtLbc$
> _______________________________________________
> sPHENIX-software-l mailing list
> sPHENIX-software-l AT lists.bnl.gov
> https://lists.bnl.gov/mailman/listinfo/sphenix-software-l