1. Particle Physics and The Standard Model
Four Fundamental Forces:
Carrier affects Carrier prop.
Gravitation graviton mass m=0 q=0 I=2
range ∞
Electromagnetic photon charge m=0 q=0 I=1
Weak W’s and Z all m=82/91 q+1,-1,0
chirality neutrinos I=1 range 10-19[m]
Strong gluon nucleons m=0 q=0 I=1
range 10-15[m]

2. Standard Model continued
How to cook up a standard model:
Take a clean slate and add General Relativity and Quantum Mechanics
This gives you the 4 fundamental forces, the ranges over which they act and
what they act on, the rules for mass, charge, and spin.
Then add a Particle Zoo:
Three particles made the periodic table – how many
particles might there be at the next lower level? One? Hundreds?
• Protons, neutrons, and electrons to make a Periodic Table of Elements
• Fermions and Bosons
• matter and antimatter

3. Anti-particles have some opposite properties (charge, spin) than normal matter.
eg positrons
When matter and anti-matter meet they annihilate. The universe has much matter and
little anti-matter left in it. Why, we don’t know.
Other particles: muons and pions:

4. After more study:

5. Conservation laws:
Energy conservation
Momentum conservation
Angular momentum conservation
Charge conservation
Baryon/Hadron conservation
Lepton conservation
Strangeness conservation

6. After more study: not all of these are fundamental
~ some leptons are (as far as we know)

7. Allowed and Forbidden Reactions:

8. More to consider: strangeness
Simplification of the Particle Zoo: Quarks

9. After more study:

10. How quarks make particles:

11. Baryons are 3 quark combinations:

13. The Standard Model Completed
1970
1975
tau discovered

14. is called Quantum-Chromodynamics.
1995 top quark discovered
Quark
flavors
The theory behind the physics of the Standard Model of Particle Physics
is called Quantum-Chromodynamics.
Together with GR and QM this model of the universe is called the
‘Standard Model’.
Its greatest flaw: GR and QM work at different ends of the length scale
spectrum and seem to be incompatible with each other.