The proton-antiproton collision produced a Higgs particle, which decayed to two b-quarks (seen in the detector as energy in the calorimeter, and indicated by the red arrows at 11 and 5 o'clock), together with a W boson, whose decay products are an electron (the green track at two o'clock) and a neutrino (inferred from an imbalance in overall momentum - the blue arrow at twelve o'clock).
http://www.fnal.gov/pub/now/live_events/explain_det_dzero.html
In this simulation, a collision between an energetic electron and positron creates a Higgs boson and a Z boson. (Image Norman Graf)
http://www.lbl.gov/Science-Articles/Archive/sabl/2005/February/ILC.html