The Mu- (left-down in x,y projection) has 13.9 GeV/c, is MIP in the HPC, deposits 10.8 GeV in the first layer of the HAB but is MIP in the other 3 layers and has hits associated in both planes of the MUB. It is also a probable muon, but is close to the neighbouring jet.
The invariant mass of the muon pair is 24.0 GeV and its recoil mass is 61.4 GeV. This event was kept in the selection of Higgs candidates.