Booklet 2A - Particles (Factual) Flashcards
What is the Standard Model?
The Standard Model explains what the basic building blocks of matter are and how they interact, governed by four fundamental forces.
Where does the evidence for the existence of quarks come from?
High-energy collisions between electrons and nucleons, carried out in particle accelerators.
What is a fundamental particle?
A fundamental particle is one that cannot be broken down into any sub particles.
What is a Fermion?
It is a fundamental matter particle.
What are the two types of Fermions?
Quark
and
Lepton
What are the names of the 6 types of Quarks?
- Up
- Down
- Charm
- Strange
- Top
- Bottom
What are the names of the 6 types of Leptons?
- Electron
- (Electron) neutrino
- Muon
- Muon neutrino
- Tau
- Tau Neutrino
What is meant by a Hadron?
Particles made from quarks
What are the two types of Hadrons?
Baryon
and
Meson
What is meant by a Baryon?
Baryons are made from 3 quarks
What is meant by a Meson?
Mesons are made from 2 quarks.
They always consist of a quark and an antiquark pair.
Give an example of a Baryon.
Proton
Neutron
How does an antimatter particle compare with a matter particle?
Antimatter particle has identical properties to the matter particle but equal and opposite charge.
What evidence is there for antimatter?
Production of energy in the annihilation of particles (e.g. positrons and electrons used in PET scanners)
Positrons discovered occurring naturally in cosmic rays.
Anti-neutrinos produced as part of Beta Decay.
Name the force-mediating particles (Bosons).
Photons
W and Z Bosons
Gluons
What force is mediated by a photon?
Electromagnetic Force
What force is mediated by W and Z bosons?
Weak force
What force is mediated by a Gluon?
Strong force
What is the force-mediating particle for the Electromagnetic Force?
The Photon
What is the force-mediating particle for the Weak Nuclear Force?
W and Z bosons.
What is the force-mediating particle for the Strong Nuclear Force?
The Gluon.
A proton is made up of two up quarks and a down quark. The up quarks are both positively charged. Why does the proton not get torn apart?
The attractive Strong Nuclear force between the quarks is greater than the repulsive Electromagnetic force between them.
Describe beta (minus) decay?
Beta (minus) decay is when a neutron decays into a proton releasing an electron and an antineutrino.
What did beta decay provide the first evidence for?
The existence of neutrinos/antineutrinos.
Why were neutrinos suggested as an extra particle produced as a result of beta decay?
When beta decay occurs momentum and energy should be conserved. This didn’t appear to be true when the proton and beta particle were considered on their own. There had to be another particle that accounted for the rest of the energy/momentum.
In physics what is meant by a field?
It is the region where an object experiences a force.