The Weak Interaction

This lecture covers the concept of parity in quantum mechanics, discussing how the parity operator performs spatial inversion and its implications on observables. It delves into the intrinsic parities of fundamental particles, the conservation of parity in QED and QCD, and the V-A structure of the weak interaction. The lecture also explores the chiral and helicity structures of QED and the weak interaction, showcasing how helicity plays a crucial role in weak interactions. Evidence for the V-A nature of the charged current weak interaction is presented, along with discussions on the weak charged current propagator, Fermi theory, and the strength of the weak interaction.