Welcome to the Masterclass computing exercise! In this, you will learn about the Z0 boson, how it decays, and how to identify the decay modes using events from the ALEPH detector at the LEP collider. Distinguishing between different decay types will allow us — together — to test an important prediction of the Standard Model.
Briefing
Before you get started, you should know some more detail about the Z0 boson, the ALEPH experiment, how to identify different decay modes, and the R parameter you will be trying to measure. You will find this covered in this description page as well as your handout:
Quiz
When you are ready, proceed to the quiz via the link below. You will first view a series of events and practice categorising them into the four kinds of decay we're studying here: electron, muon, tau, and hadronic jet. You will get feedback so you can better learn to identify them.
At first you will see an even mix of the four decay types, for practice purposes, then we will switch to "real" measurement where you can apply your new skills. The results will be recorded, and at the end we'll see how your measurement of the hadronic/leptonic decay ratio compares to the accepted value.
Afterwards
When you have finished this exercise, if you still have time, navigate to the Lancaster app to try your hand at reconstructing an even rarer particle than the Z0: the Higgs boson.