Someone argues: "The baryon decays as with a measured mean lifetime of
PHYSICS · Subjective · Fermi University Physics · Particle Physics & Quantum Fields · Particles, interactions and experiment · Particles, interactions and experiment
Particle Physics, Ch The particle zoo and the four interactions
Problem
Someone argues: "The Σ0 baryon decays as Σ0→Λγ with a measured mean lifetime of 7.4×10−20s. This is many orders of magnitude shorter than the charged pion's 2.6×10−8s, and a short lifetime means a strong decay, so the Σ0 must decay by the strong interaction." Find the error in this reasoning and state which interaction is actually responsible for the Σ0 decay.