PHYSICS · Multi-part · Fermi University Physics · Particle Physics & Quantum Fields · Symmetry, groups and the quark model · Flavour, neutrinos and CP violation
Particle Physics, Ch Parity, charge conjugation, time reversal and CPT
Problem
The K∗0(892) meson has JP=1−, strangeness S=+1, and is measured to have a width Γ=47.3MeV, decaying almost entirely to Kπ, two thirds of the time as K+π− (with S(K+)=+1, S(π−)=0).
((a)) Compute the mean lifetime of the K∗0 from its width, and use it together with the strangeness bookkeeping of the initial and final states to decide which of the four fundamental interactions drives this decay.
((b)) Given P(K+)=−1 and P(π−)=−1, use the multiplicative parity rule appropriate to that interaction to decide whether K∗0→K+π− is allowed, and check the result against the fact that this is the dominant decay mode of the K∗0.
((c)) State briefly why confirming parity conservation in this decay tells us nothing about whether CP is conserved in the weak decays of neutral kaons, and quote the fraction that established that CP is in fact violated there.