  We consider the ground state and the ground state energy of an atom with
spinless electrons in the framework of non-relativistic qed. We show that the
ground state energy as well as the ground state depend analytically on the
parameters of the group of dilations, the parameter of a group of spatial
dependent phase changes, and on the minimal coupling constant. As a corollary
we obtain spatial exponential decay of the ground state as well as of its
dilation analytic extension. No infrared regularization is needed for the
result. Our result is based on operator theoretic renormalization.
