Pair production of open strings - relativistic versus dissipative dynamics

We study the pair production of open strings in constant external electric fields, using a general framework which encodes both relativistic string th eory and generic linearly extended systems as well. In the relativistically invariant case we recover previous results, both for pair production and f or the effective Born-Infeld action. We then derive a non-relativistic limi t - where the propagation velocity along the string is much smaller than th e velocity of light - obtaining quantum dissipation. We calculate the pair nucleation rate for this case, which could be relevant for applications, (C ) 1999 Elsevier Science B.V.