particle classification

Question 1

Bosons

Answer 1

bosons are exchange particles

• transfer forces across
• do not obey the Pauli Exclusion Principle, so can occupy the same space as another particle

Question 2

Fermions

Answer 2

• do obey Pauli Exclusion Principle

* all particles are either bosons or fermions

Question 3

examples of bosons

Answer 3

photons - exchange bosons for the electromagnetic force

W-particles - exchange particles for the weak nuclear force

Question 4

fermion classifications

Answer 4

• LEPTONS: fundamental particles which feel the weak but not strong nuclear force
• HADRONS: not fundamental (made of quarks) and feel both weak and strong nuclear forces

Question 5

examples of leptons

Answer 5

• electrons (e-)
• muons (µ-) heavy unstable electrons
• each have antiparticles (e+ and µ+)
• (muon)neutrinos and antineutrinos (Ve, /Ve and Vµ and /Vµ) low mass, neutral charge

Question 6

hadron classification

Answer 6

• BARYONS have 3 quarks

- MESONS lower mass than baryons, made up of quark and antiquark

Question 7

examples of baryons

Answer 7

• protons, neutrons and their antiparticles
• protons are the only stable baryon
• isolated neutrons decay under the weak interaction

Question 8

examples of mesons

Answer 8

• pions (π+, π-, π0) most common and stable meson, virtual pions are the exchange particle of the SNF between nucleons
• kaons (K+, K-, K0) the most common “strange” particle

Question 9

mesons - strange particles

Answer 9

• longer half-lives than expected
• always formed by the SNF but decay by the weak force
• kaons might decay to pions via the weak interaction