Someone argues: "The neutral kaon and antikaon masses agree only to within a…
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
Someone argues: "The neutral kaon and antikaon masses agree only to within a fractional limit of about 10−18, not exactly. Since the CPT theorem asserts that particle and antiparticle masses are exactly equal, this measurement has not actually tested anything: it can never do more than confirm an assumption that was already built into the definition of an antiparticle."
((a)) Find the error in this reasoning.
((b)) State what kind of statement the CPT theorem is, and what would count as evidence against it.