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 J/ψ meson is a neutral, self-conjugate vector state with C(J/ψ)=−1 (given). No electromagnetic decay J/ψ→γγ has ever been observed. Recall that a single photon has C(γ)=−1.
((a)) Find the charge conjugation eigenvalue of a two-photon final state.
((b)) State whether J/ψ→γγ is allowed by charge conjugation, and comment on whether this is consistent with the mode never being seen.