Quantum scattering in the presence of a constant electric field ('Stark eff
ect') is considered. It is shown that the scattering matrix has a meromorph
ic continuation in the energy variable to the entire complex plane as an op
erator on L-2(Rn-1). The allowed potentials V form a general subclass of po
tentials that are short-range relative to the free Stark Hamiltonian: Rough
ly, the potential vanishes at infinity, and admits a decomposition V = V-A
+ V-e,where V-A is analytic in a sector with V-A(x) = O([x(1)](-1/2-epsilon
)), and V-e(x) = O(e(mu x1)), for x(1) < 0 and some mu, epsilon > 0. These
potentials include the Coulomb potential. The wave operators used to define
the scattering matrix are the two Hilbert space wave operators.