Decay of Excited String States at Colliders and Cosmic Ray Detectors

It is argued that in the context of TeV gravity with large extra dimensions, excited string states produced in colliders and in the interaction of cosmic rays with the atmosphere may decay preferentially into invisible bulk modes, rather than visible gauge fields on the brane. This contrast to the black hole case comes about because of the absence of a relationship between physical size and temperature for string ball states. We estimate the effect of this upon the number of events predicted at cosmic ray observatories and colliders.