sPHENIX tracking discussion

[Christof Roland <christof.roland AT cern.ch>]

Hi,

when scanning a few g4hit and g4particles examples to see how to reorder things to speed up the SvtxEvaluator

I stumbled upon a a few things i can't explain. the plots below show the r and z positions of a out of time pileup

track (gt = 6468.2). One plot shows the g4hit positions in the TPC at the production time of the particle and 

the other plot shows the matched cluster positions, including the z shift due to the drift time.

The thing I need help understanding is how the reco clusters matched to the g4particle can form 

a straight line across the central membrane?

Also the structure at the sector boundaries looks suspicious.

Please let me know if you have an explanation for either effect. 

Thanks 

    Christof