GROUND-STATE RESONANCES OF A HYDROGEN-ATOM IN AN INTENSE MAGNETIC-FIELD

We consider a hydrogen atom in a constant and very large magnetic fiel d. For bounded angular momentum about the direction of the magnetic fi eld we consider resonances in the sense of dilation analyticity. We fi nd a class of resonances corresponding to quasi-stationary states whic h behave in a certain sense like ground states. The position of these resonances in the complex plane is estimated. Further it is shown that under the time evolution generated by the Hamiltonian for this system these quasi-stationary states exhibit exponential decay in time.