Rare Decays in Theories with LGS

Gravitational decays in particle physics are expected to violate the B and L quantum numbers. In the standard theory, where gravity is weak because of the huge value of Planck mass, the observation of the phenomenon is far from present and probably future experimental sensitivity. On the other hand, in theories with low gravity scale, where gravity becomes stronger at shorter distances, these processes may be dangerous, predicting a too short proton lifetime. Here I discuss a possible picture of gravitational decays, which is consistent with present experimental bounds for a true gravity scale of few TeV and suggests the possibility of observing B and L violating decays with a minor improvement of the present experimental capability.