Gauge bosons

9.7 Fundamental interactions:

Relative strength of the fundamental forces 

Vector gauge  bosons

• Photon:     Electromagnetic force     Electric charge      U(1) 

•  W+  W-   Z:      Weak force      Weak charge       SU(2)

• Gluon:       Strong nuclear force       Color     SU(3)     

Scalar boson

• Higgs boson     Mass generation     

 Basic Feynman diagrams

• Emission of exchange particle

• Absorption of exchange particle

• Pair production

• Pair annihilation

More complicated Feynman diagrams

9.4 Exchange particles  have  spin=1   aka  gauge bosons:

• Electromagnetic force:      photon

• Strong nuclear force:     gluons      ( outdated - pions)             

• Weak nuclear force:     W+  W-   Z