When a Z0 decays to produce a back-to-back quark-antiquark pair we will expect to see a back-to-back pair of jets in the detector. Most of the particles in these jets are hadrons. We therefore see a number of charged particle tracks and energy deposits in both the electromagnetic and hadronic calorimeters.
Here are a couple of example events.
End-On View of Event
Side View of Event
Note that there may sometimes be a few particles that are produced at a large angle to the two jets. However, these tend to be fairly low momentum particles (as can be seen in this event by the fact they are colour-coded yellow and green). The high momentum particles tend to be close together in the centre of the jet.
Sometimes a jet may contain an electron or muon as well as hadrons, as is the case in the second example:
Example
Event No. 2
End-On View of Event
Side View of Event
Identifying Events Containing a Particle-Antiparticle Pair