(a) The meson has a total decay width (PDG 2024). Treating this as the only source of…

PHYSICS · Subjective · Fermi University Physics · Particle Physics & Quantum Fields · Particles, interactions and experiment · Particles, interactions and experiment

Symmetry and Flavour, Ch Four-vectors at work: boosts, invariants and the shape of a final state

Problem

(a) The

J/\psi

meson has a total decay width

\Gamma = 92.6\,\mathrm{keV}

(PDG 2024). Treating this as the only source of decay, calculate its mean lifetime in seconds. (b) A cross section worked out in natural units comes to

\sigma = 2.0\times10^{-6}\,\mathrm{GeV^{-2}}

. Express it in nanobarns and in

\mathrm{cm^2}

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