Low Temperature Hydrogen Antihydrogen Interactions

In view of current interest in the trapping of antihydrogen ( ) atoms at low temperatures 1–3], we have carried out a full four-body variational calculation to determine s-wave elastic phase shifts for hydrogen antihydrogen scattering, using the Kohn Variational Principle. Terms outside the Born–Oppenheimer approximation have been taken into account using the formalism of Kołos and Wolniewicz 4]. As far as we are aware, this is the first time that these terms have been included in an H scattering calculation. This is a continuation of earlier work on H– interactions 5–7]. Preliminary results differ substantially from those calculated using the Born–Oppenheimer approximation 8–10]. A method is outlined for reducing this discrepancy and taking the rearrangement channel into account. This revised version was published online in August 2006 with corrections to the Cover Date.