What exactly is a lepton number of a particle? With the charge (eg proton is just 1, not the exact charge), I can understand because it's a physical property, put a particle with charge + next to another particle with charge + and they will repel.
What is the lepton number in similar terms? Or is it just a convention that worked in the observable particle interactions (that it is conserved, like charge)
[Physics] lepton number
leptonsparticle-physicsstandard-model
Best Answer
Electric charge is a "special" kind of physical property because it corresponds to a very simple physical effect. But that's not true of most physical properties. The lepton number doesn't have any force associated with it, the way electric charge does, because it's not a coupling constant.
Lepton number is just a mathematical expression of what it means to be a lepton. The quantum fields which correspond to the particles we call leptons (electron, muon, tau, and their corresponding neutrinos) each have a lepton number of 1, and the fields corresponding to their antiparticles each have a lepton number of -1. Lepton number is considered to be a useful property because it is conserved in all observed reactions.