Fundamental forces 

Forces and exchange particles 

Three line vertices 

Relative strength of the fundamental forces 

Exchange particles

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

Exchange particles  have  spin=1   aka  gauge bosons:

Electromagnetic force:      photon

Strong nuclear force:     gluons      ( outdated - pions)             

Weak nuclear force:     W+  W-   Z