Particle Physics Flashcards
What is a baryon?
A heavy hadronic, subatomic particle made up of 3 quarks. Protons and neutrons are shown to be baryons
What are hadrons?
They are a class of heavy particles that can interact via the strong, weak, gravitational and electromagnetic force. The subclasses underneath hadrons are baryons, mesons and their antiparticles
6 flavours of quarks
up,down,top,bottom,strange and charm
What are the 4 fundamental forces?
Gravitational force
Electromagnetic force
Strong nuclear force
Weak nuclear force
What are the exchange particles between the fundamental forces and matter?
Gravitational force- Graviton (theoretical)
Electromagnetic force- ‘Virtual photons’
Strong nuclear force- Gluons
Weak nuclear force- W+, W-,Z bosons
What are antiparticles?
Antiparticles are particles that mirror our real world particles but only have opposite charge. When a particle and antiparticle collide/interact they annihilate each other and release two photons and convert into a lot of energy.
Beta-negative decay
When a neutron because of unstable and heavy nucleus and changes into a proton, an electron and an antineutrino. The W- boson of the weak nuclear force causes this interaction
Beta-plus decay
When a nucleus that has too many protons (unstable) will have a proton change into a neutron, a positron and a neutrino. The neutron is retained and the positron and neutrino are emitted. The W+ boson of the weak nuclear force causes this interaction.
What are mesons?
A heavy hadronic, subatomic particle made up of only a quark and antiquark
How to calculate specific charge of an nucleus?
- Find the number of protons and multiply by 1.60 x 10^-19
- Find the number of nucleons and multiply by 1.67 x 10^-27
- Substitute the values of each of them into specific charge equation
How does the strong nuclear force change at different lengths?
The force is repulsive below 0.5 femtometres stops neutrons and protons being pushed into each other. The force is attractive until it reaches a maximum of 3 femtometres then it falls rapidly at 4 femtometres to 0 having no effect
Pair Production
Under special circumstances, when a photon interacts with an atom or nucleus it can convert its rest energy into mass of a particle-antiparticle pair through e=mc^2. The photon must have enough energy to create the two particles
Which force do strange particles interact through?
Strong force
Which force do strange particles decay through and where is it not conserved?
Weak force
What are leptons?
Light-weight particles that aren’t made up of anything else and only interact through the weak, electromagnetic and gravitational forces
Ionisation energy
the minimum amount of energy required to remove an electron from an atom
Excitation energy
the energy required to move electrons to higher energy levels in an atom
