Topic Menu

Cyber-chess a chess instruction site
Particle Physics Questions

Q5.

Sub-atomic particles can either be hadrons or leptons.

(a) State one difference between these two groups of particles.

Leptons do not experience the strong interaction but hadrons do.

or

Hadrons are not fundamental particles. They are made up of quarks but leptons are fundamental.

Note that when stating the difference you need to specify the properties of both sets of particles. Saying Hadrons experience the strong force without explaining that leptons don't will not get you a mark!

(1 mark max)

(b) Give an example of

(i) a non-strange hadron proton, neutron or pion

(ii) an example of a lepton electron, muon, tauon or neutrino (tau, mu or electron variety)

(2 marks)

(c) Hadrons can be further divided into two groups. Name these two groups and state a difference between them.

Baryons Mesons

Baryons are made from three quarks (or three antiquarks) whereas mesons are a quark–antiquark pair

or

Baryons have baryon number of +1 or –1 (for the antibaryon) whereas mesons have baryon number 0

Note again that when stating the difference you need to specify the properties of both sets of particles to gain the mark. Don't be lazy when answering a question!

(3 marks)

(Total 6 marks)