PowhegControl: update of ttjMiNNLO AGENE-2055 and first implementation of 4tops process AGENE-2128
requested to merge atlas-physics/pmg/mcexperts/powheg-experts/athena:21.6-Powheg_UpdatettjNNLO_Add4tops into 21.6
As the title suggests, this makes an update of the ttjMiNNLO process (now using public code from authors) and makes a first implementation of the interface to the 4tops process, in Powheg. Both would need to be tested using export POWHEGPATH=/afs/cern.ch/atlas/offline/external/powhegbox/ATLASOTF-05-02.
More details are given in the ticket.