Electric-field influence on doubly excited Feshbach resonance states of the positronium negative ion below the N=3 threshold of the positronium atom - art. no. 022510

We present a study of the influence of the constant uniform electric field on the doubly excited resonances of the positronium negative ion associated with the N=3 positronium threshold. The calculation is performed in the fr amework of the complex coordinate rotation method which obtains results bot h for the real part of the energy (position of the resonance) and for the i maginary part of the energy (related to the width of the resonance). Result s are given for the M = 0 Stark components of the Feshbach S-1(e)(1), P-1(o )(1), and D-1(e)(1) resonances.