Particle Physics Flashcards
List the four fundamental forces from weakest to strongest.
- Gravitational
- Electromagnetic
- Weak Nuclear
- Strong Nuclear
List the range, affects, purpose and magnitude of gravitational force.
R - Infinite
A - All particles
P - Attracts all matter
M - 10-³⁸
List the range, affects, purpose and magnitude of electromagnetic force.
R - Infinite
A - Charged particles
P - Atomic bonding
M - 10-²
List the range, affects, purpose and magnitude of weak nuclear force.
R - 10-¹⁸m
A - All particles
P - Beta decay
M - 10-⁷
List the range, affects, purpose and magnitude of strong nuclear force
R - 10-¹⁵m
A - Nuclear material (eg protons, neutrons)
P - Binds nucleus
M - 1
What is the Grand Unified Theory (GUT)?
The GUT merges electromagnetic, weak nuclear and strong nuclear forces into one law of interaction.
What is the Theory of Everthing?
It integrates the gravitational force with the three other forces.
What are the conservation laws?
- Conservation of mass/energy
- Conservation of momentum
- Conservation of charge
What is the Cockcroft and Walton experiment?
It is the first transmutation using artificially accelerated particles. This was done in a linear accelerator.
Describe Cockcroft and Walton’s experiment.
- A hydrogen-discharge tube produces protons (hydrogen nuclei) which are introduced into the column.
- A decreasing high voltage supply of 400kV-0V accelerate the protons towards the bottom of the tube.
- The proton strikes a lithium target at 45° to the proton beam.
- This produces two alpha particles (helium nuclei) moving 180° apart, left and right of the plate.
- The alpha particles strike a zinc sulphide screen, which causes scintillations.
- Each flash is observed by looking through a microscope on either side of the target.
State the relevance of the Cockroft and Walton experiment.
- First particle accelerator
- First artificial splitting of an atom
- First transmutation of an atom
- Verification of E=mc²
What is the equation produced from the Cockcroft and Walton experiment?
Li + H = He + He + EK
What is a proton proton collision equation?
p + p + Q1 = p + p + additional particles + Q2
What was the solution to missing momentum?
Neutrino
What are the benefits of circular accelerators over linear accelerators?
Higher speeds can be reached, therefore there is more kinetic energy, thus more new particles can be created
What is antimatter?
Antimatter is matter composed of antiparticles. Antimatter has identical mass but opposite charge and quantum spin to the original particle
What is pair production?
The simultaneous creation of a particle and its antiparticle from electromagnetic energy
State an equation for pair production.
Y = e- + e+ + EK + v(neutrino)
What is pair annihilation?
The conversion of a particle and its corresponding antiparticle into electromagnetic energy
State an equation for pair annihilation.
e- + e+ + EK= 2Y + v(neutrino)
What is the particle zoo?
The zoo divides particles accordingly to which fundamental force affects them, their size and other characteristics to do with magnetic and quantum spin
What is a quark?
An elementary particle which experiences all four fundamental forces and forms a basic constituent of matter
What are the six flavours of quark?
Up, down, top, bottom, charm, strange
What are leptons?
Leptons include all fundamental particles which are not subject to the strong nuclear force but are affected by the others. eg electron, muon, tau
What are hadrons?
Hadrons are particles that feel all four forces. They are split into baryons and mesons
What are baryons?
Particles composed of 3 quarks or antiquarks. They have a mass greater than or equal to that of a proton. eg proton, neutron, lambda, sigma
What are mesons?
Particles composed of a quark and antiquark. They are between the size of an electron and proton. eg pion, kaon
What is the quark composition of a proton and a neutron?
Proton = uud
Neutron = udd
