A way of studying a collision event of the kind recorded by the L3 detector is to draw a picture which shows where the particles were detected and how much energy they deposited in the different parts of the detector. These pictures are obtained using computer programs which reconstruct all the single parts of L3 and determine what happened in them. Here are some examples of actual event displays; click on the pictures to get enlarged versions. The size of the coloured boxes indicates the energy deposited in the different parts of the detector.

The pictures above are two views of the same hadronic event: a pair of b ("bottom") and anti-b quarks is produced and decay in a very short time into more stable particles which are detected. In the picture on the left one can see several tracks left in the Time Expansion Chamber (TEC) by charged particles: they are the coloured lines starting from the center of the detector. Notice that this is a transverse view, which means that the electron-positron beam would be perpendicular to your screen. In the upper part of the image there are two big rectangles which represent the energy left by a positron in the electro-magnetic calorimeter (BGO). The figure on the right is an enlarged view in which also the muon detectors are shown. The line crossing the lower part of the detector is the path followed by a muon, another particle coming from the decay of the original pair.
Above: a tau and anti-tau pair is produced and the decay products are detected. A transverse view is shown on the left. The top left tau decays into an electron and a large amount of energy is deposited in the electro-magnetic calorimeter. The second tau (bottom right) decays into three charged particles (hadrons). The longitudinal section of the same event is shown in the picture on the right.

If you want to see more events (ps format), click HERE.