A pattern evolves, 1952–1964.
Most of the particles whose discoveries are described in the preceding chapters have lifetimes of 10−10 s or more. They travel a perceptible distance in a bubble chamber or emulsion before decaying. The development of particle accelerators and the measurement of scattering cross sections revealed new particles in the form of resonances. The resonances corresponded to particles with extremely small lifetimes as measured through the uncertainty relation Δt ΔE = ħ. The energy uncertainty, ΔE, was reflected in the width of the resonance, usually 10 to 200 MeV, so the implied lifetimes were roughly ħ/100 MeV ≈ 10−25 s. As more and more particles and resonances were found, patterns appeared. Ultimately ...