Draft: Add fat jet parent ghost particles
I think the ghost particles we use right now for GN2X might be getting groomed away by soft drop. Maybe we should try to match to the parent and pull the ghost tracks off there. Unfortunately this breaks now because we didn't store the GhostTrack
links in the parent jets, see atlas/athena!74420 (merged).
Adding @rles for some reason, and also @jabarr for some other reason.
Edited by Dan Guest