International Physics Masterclasses

Content

Measurement
Analysis

Exercise 2

With the following exercise, you can test how good your command of event identification is. Therefore we have chosen ten examples. They are stored here in electronic form for you to download. At the International Masterclasses, they are already stored on your computer desktop. They have to be read in the program MINERVA (with “Read Event Locally”).

Your task is to distinguish between signal and background events. Signal events are only events, which produce exactly one W particle. In signal events you also determine whether the W particle has decayed into an electron or positron or into a muon or antimuon, and the associated (anti-)neutrino. Events with jets, Z particles, and top-quark pairs are background events.

You can check your results using the table below. For each event, choose which process you think is underlying the event. By clicking “Confirm Task”, you can find out the number of events identified correctly. By clicking “Correct Answers”, you can see the correct answers.

Have fun on the test!

Event W⁺→e⁺+ν_e W^-→e^-+
ν
_e W⁺→μ⁺+ν_μ W^-→μ^-+
ν
_μ background

example 1

example 2

example 3

example 4

example 5

example 6

example 7

example 8

example 9

example 10

Event	W⁺→e⁺+ν_e	W^-→e^-+ ν _e	W⁺→μ⁺+ν_μ	W^-→μ^-+ ν _μ	background
example 1
example 2
example 3
example 4
example 5
example 6
example 7
example 8
example 9
example 10