Physics - Feynman Diagrams

Physics - Feynman Diagrams

1. Electromagnetic repulsion - when two particles get close to each other and repel. Two electrons e- or two positrons e+.

2. Electron capture and electro-proton collision - electrons and protons are attracted by the electromagnetic interaction between them, but if a proton captures an electron, the weak interaction can make this interaction happen. P + e- ---> n + Ve. For electron-proton collision the n ----> p with a W- boson.

3. Beta-plus, n ---->p + e- + anti Ve

   • Beta-minus, p ---->n + e+ + Ve
     • You get an antineutrino in B- decay and a neutrino in B+ decay so that lepton number is conserved.

4. RULES FOR DRAWING PARTICLE INTERACTION DIAGRAMS - 1. Incoming particles star at the bottom and move up. 2. The baryons and leptons can't cross from one side to the other. 3. Charges on both sides need to balance, the W bosons carry charge from one side of the diagram to the other. 4. The W- boson going to the left has the same affect as the W+ boson going to the right.