What is the Standard Model
The classification of fundamental particles and how they interact with the four fundamental forces.
Why don’t we see other fundamental particles and just protons, electrons, neutrons etc.?
Because the other fundamental particles decay quite easily, and we can only see them by accelerating particles like protons and colliding them.
What are antimatter equivalents?
All subatomic particles have antimatter equivalents with same mass but opposite charge (unless they’re neutral).
What is annihilation?
When a matter particle collides with its antimatter particle, they will disappear and all mass is converted to energy. This energy is released as a pair of equal energy gamma rays travelling in opposite directions (to conserve momentum).
What can we use to calculate the energy of gamma rays emitted by annihilation?
E = mc^2
What are fundamental forces?
Forces that cannot be explained in terms of simpler forces. E.g. Contact force of standing on the ground is not a fundamental force bc it can be explained in terms of electromagnetic force; the electrons in the atoms of the feet and the ground repel.
For this reason, quantum physics states touch can never actually occur.
What are the four fundamental forces?
- Electromagnetic
- Gravitational
- Strong nuclear (force of attraction between adjacent nucleons that prevents the nucleus from being blown apart as protons repel)
- Weak nuclear (Governs the process of beta-plus decay - proton to neutron - and beta-minus decay - neutron to proton)
What are gauge bosons?
Force-carrying particles that explain the attraction in strong nuclear and weak nuclear forces. Exchanging these force-carrying particles causes attraction or repulsion.
Think of it like grabbing or throwing a heavy object in a frictionless environment, and how that’d move your body.
What are the unique gauge bosons for each fundamental force?
Electromagnetic - photons (not light)
Strong nuclear - gluon (exchanged between quarks)
Weak nuclear - W and Z bosons
Gravitational - undiscovered
Forces with infinite range (electromagnetic and gravity) must have gauge bosons with 0 mass.
W & Z bosons have mass, gluons don’t but an involved intermediate particle does (the pion).
What are leptons?
Fundamental particles acted upon by the weak nuclear force but not by the strong nuclear force.
There are six protons: Electron, muon, tau (all negative), electron neutrino, muon neutrino, and tau neutrino particles (all neutral).
What are lepton numbers
There are three: Electron lepton number, muon lepton number, and tau lepton number
Each number will have a value of +1 for its associated lepton and 0 for the rest. It will be -1 for its antimatter counterpart.
What are hadrons and quarks
Particles that interact via both strong and weak nuclear forces. They are made up of smaller fundamental particles called quarks
Only up and down quarks are stable.
What are baryons
Particles made of three quarks bound together
What are mesons
Particles made of two quarks bound together, where one is regular and the other is antimatter.
The particle would explode if the two quarks are the same, because a matter particle and equivalent antimatter particle annihilate.
What are baryon numbers
All quarks have a baryon number of +1/3, antiquarks have a baryon number of -1/3.
Baryons have a baryon number of 3*1/3=+1 (antimatter counterparts have -1), and mesons have a baryon number of 1/3 + -1/3 = 0. Leptons do also as they are NOT hadrons.
This number is always conserved in reactions.
