CPT, Strings, and the $K \bar K$ System
  This talk contains a summary of our work on dynamical CPT invariance and spontaneous CPT violation in string theories, including the possibility that stringy CPT violation could occur at levels detectable in the next generation of experiments. In particular, we present here an estimate for values of parameters for CPT violation in the kaon system. 
Alan Kostelecky and Robertus Potting