[Halld-offline] [EXTERNAL] request for help from tracking group

[Richard Jones]

Hello all,

I have been looking into differences between geant4 and geant3 simulations
of k+ tracks at backward angles in the cdc, and have discovered what
appears to be a sudden failure of the tracking past about 120 degrees in
the cdc. Please see the final plot and comments here.

https://urldefense.proofpoint.com/v2/url?u=https-3A__github.com_JeffersonLab_HDGeant4_issues_137-23&d=DwIBaQ&c=CJqEzB1piLOyyvZjb8YUQw&r=Te_hCR4EUlJ6iCDYLJ8Viv2aDOR7D9ZZMoBAvf2H0M4&m=nHXw_4MCbSbzhcXPApg4pe8vH25eBETYPBlvns7oYvc&s=hLAiYzGqBJ5IdrEeCh6QrJksU3v12FUHm44NA63CNEc&e= 

>From hdview, I see that the number of hits on the track is very good up
through DTrackTimeBased, and visually things look quite clean but the FOM
values are terrible and there are no combos being generated. I am not sure,
but don't combos need to be generated for these tracks to go further down
the reconstruction chain? A set of 100 such tracks is available at:

https://urldefense.proofpoint.com/v2/url?u=https-3A__zeus.phys.uconn.edu_halld_kstudy-2D4-2D2020_kstudysim-5Fsmeared.hddm&d=DwIBaQ&c=CJqEzB1piLOyyvZjb8YUQw&r=Te_hCR4EUlJ6iCDYLJ8Viv2aDOR7D9ZZMoBAvf2H0M4&m=nHXw_4MCbSbzhcXPApg4pe8vH25eBETYPBlvns7oYvc&s=_XamR5Vx21DbQ5ZVCPiOB7ruQRpqTn3LhQJB_rO3Loo&e= 

-Richard Jones
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