Fundamental Particles Flashcards
What are the Four Fundamental Forces
- Gravity
- Weak Nuclear
- Electromagnetic
- Strong Nuclear
What are the Fundamental Particles Carried by and Act on
What are Exchange Particles
Particles that carry energy and momentum between elementary particles
What are the Feynman Diagram Rules
- Particles are represented by straight lines
- Exchange particles are represented by wavy lines
- Particles are annihilated and created at the vertices
What is the Advantage of Feynman Diagram over symbol equation
The feynman diagram shows us the interactions that occur rather that just what goes in and what comes out
Describe the Beta Minus Decay Feynman Diagram
- n = neutron
- p = proton
- W- = exchange particle
- e- = electron
- ̅νe= electron antineutrino
Describe the Beta Plus Decay Feynman Diagram
- p = proton
- n = neutron
- W+ = exchange particle
- e+ = positron
- ve = electron neutrino
What is Electron Capture
When an electron is absorbed by a proton so the proton decays into a neutron and a neutrino, a W+ exchange particle is exchanged
Describe the Electron Capture Feynman Diagram
What is Electron Proton Collision
When a proton and electron collide, the proton turns into a neutron and the electron turns into a neutrino, a W- exchange particle is exchanged
Electron Proton Collision Feynman Diagram
What are Quarks
Fundamental particles, there are 6 and they are composite (come in pairs)
What are the Flavours of Quarks
- Up
- Down
- Top
- Bottom
- Charm
- Strange
Describe the Classification of Particles
What does a muon decay into
Electron ( e −) + Electron Anti-neutrino + ( ̅ νe) + muon neutrino (νμ)
What are the most stable baryons
Protons are the most stable baryons because the other baryons will eventually decay into them
What are Pions
The exchange particle of the strong nuclear force
What are Kaons
A particle that decays into pions
What are the Conservation Laws
- Charge must be conserved
- The Baryon Number must be conserved
- The Lepton Number must be conserved
- Strangeness must be conserved but only in strong interactions
Apart from the Conservation Laws what two other features are conserved in interactions
Momentum and Energy
Which particles have a Baryon Number
- Baryons = +1
- Antibaryons = -1
- Non Baryons = 0
Which particles have a Lepton Number
- Leptons = +1
- Antileptons = -1
- Non Leptons = 0
What are the Properties of Strange Particles
- Produced in strong interactions
- Decay through weak interactions
- Always created in pairs
- Longer half life than expected
What is an Example of a strange particle
A Kaon
Describe Quarks during beta decay
- Beta minus Decay - a down quark changes into a up quark
- Beta plus Decay - a up quark changes into a down quark
