tauRecTools: use ghost-matching for tau-track association
Hello,
This MR is implementing a hybrid tau-track association that accepts all tracks within a cone of radius 0.25, and beyond 0.25, tracks are required to be ghost-matched with the seed jet. The ghost matching requirement prevents from using tracks from another tau (a situation that leads to very problematic behaviour in the tau substructure reconstruction, ATLTAU-1442). The motivations are explained in this talk.
The hybrid cone/ghost scheme is meant to replace the R=0.4 cone association, but it's currently disabled in tauRec.
I am adding the urgent flag because we need to validate the new scheme urgently and use it for the upcoming retuning of tau algorithms for the R22 reprocessing.
Cheers, Bertrand