Non exponential decays of hadrons
  We analyze the survival probability of unstable particles in the context of quantum field theory. After introducing the spectral function of resonances, we show that deviations from the exponential decay law occur at short times after the creation of the unstable particle. For hadronic decays, these deviations are sizable and could lead to observable effects. 
Giuseppe Pagliara and Francesco Giacosa
hep-ph quant-ph