From Flip Tanedo at US/LHC Blog anbd Quantum Diaries: “Helicity, Chirality, Mass, and the Higgs”

I must have missed this post by Flip, it is dated June 19, 2011. It is terrific and well worth the reading.


We’ve been discussing the Higgs (its interactions, its role in particle mass, and its vacuum expectation value) as part of our ongoing series on understanding the Standard Model with Feynman diagrams. Now I’d like to take a post to discuss a very subtle feature of the Standard Model: its chiral structure and the meaning of “mass.” This post is a little bit different in character from the others, but it goes over some very subtle features of particle physics and I would really like to explain them carefully because they’re important for understanding the entire scaffolding of the Standard Model.

My goal is to explain the sense in which the Standard Model is “chiral” and what that means. In order to do this, we’ll first learn about a related idea, helicity, which is related to a particle’s spin. We’ll then use this as an intuitive step to understanding the more abstract notion of chirality, and then see how masses affect chiral theories and what this all has to do with the Higgs….

See the full post here.

Participants in Quantum Diaries:





Brookhaven Lab