Someone argues: "The has mass and quark content

PHYSICS · Subjective · Fermi University Physics · Particle Physics & Quantum Fields · Particles, interactions and experiment · Symmetry, groups and the quark model

Particle Physics, Ch SU(3) flavour and the hadron multiplets

Problem

Someone argues: "The Ω−\Omega^- has mass 1672.5 MeV/c21672.5\,\mathrm{MeV}/c^2 and quark content ssssss. The decay Ω−→Λ+K−\Omega^- \to \Lambda + K^- conserves electric charge (−1=0+(−1)-1 = 0 + (-1)) and baryon number (1=1+01 = 1 + 0), and it is kinematically allowed since M(Λ)+M(K−)=1115.7+493.7=1609.4 MeV/c2≤1672.5 MeV/c2M(\Lambda) + M(K^-) = 1115.7 + 493.7 = 1609.4\,\mathrm{MeV}/c^2 \le 1672.5\,\mathrm{MeV}/c^2. Therefore this is a strong decay, and the Ω−\Omega^- should have a lifetime typical of the strong interaction, of order 10−23 s10^{-23}\,\mathrm{s}." Find the error in this reasoning, and state which conservation law the argument overlooked, what the correct classification of the decay is, and why that classification is consistent with the measured lifetime τ(Ω−)=8.2×10−11 s\tau(\Omega^-) = 8.2\times10^{-11}\,\mathrm{s}.

Browse the problem library