PHYSICS · Multi-part · Fermi University Physics · Particle Physics & Quantum Fields · Symmetry, groups and the quark model · Symmetry, groups and the quark model
Particle Physics, Ch Parity, charge conjugation, time reversal and CPT
Problem
The neutral meson η is, like the π0, a self-conjugate state with C(η)=+1 (given). It decays electromagnetically to γγ in about 39% of its decays. Recall that a single photon has C(γ)=−1.
((a)) Find the charge conjugation eigenvalue of the two-photon final state.
((b)) State whether η→γγ is allowed by charge conjugation, and compare with the observed fraction of decays.