Leptonic decays of the Z

Leptonic decays of the Z0

The Z boson decays into any fermion pair kinematically allowed. In the following we have concentrated on the decays into charged leptons, electrons, muons or taus. The data we have selected contain these data together with other events coming from t-channel electron scattering, gamma-gamma interactions, few decays into quark pairs.

To learn how to recognize these types of events from their behaviour in the detector, we have also given samples of simulated events for these different cases. In the following you are invited to identify these events and look at some distributions which exhibit interesting behaviour. You will have the possibility to look at events in a detailed and simplified way and to build distributions using a histogramming package: PAW. Have fun!

You can start by looking at some detailed displays of events from the ALEPH data file to help understand their features.

For the rest of the exercise, you must be able to run the PAW program (Physics Analysis Workstation) on your computer. You can download PAW from CERN under certain conditions.

You should now download the following programs, which you will execute inside PAW:

A program to initialise PAW
A program to display events and a routine used by the display program
A program to histogram event variables

Download also the following data files, which are in the form of PAW ntuples:
Z to mu+ mu- Monte Carlo
Z to e+ e- Monte Carlo
Z to tau+ tau- Monte Carlo
e+e- to gamma gamma e+ e- Monte Carlo
e+e- to gamma gamma mu+ mu- Monte Carlo
e+e- to Leptons ALEPH Data

You are now ready to learn to display events with PAW, and to use PAW to plot event variables.

Finally you can do some things with Z 0 data. A few definitions should help.

Henri Videau, videauh@polhp4.in2p3.fr , March 26 1996

Joe Rothberg, rothberg@aloha.cern.ch , 12 March 1996