GLORY AND RESONANCE EFFECTS IN THE INDEX OF REFRACTION FOR ATOMIC WAVES

We have performed the first detailed calculation of the index of refra ction of a gas (argon) for an atomic wave (sodium). The index depends rapidly on the wave vector k(r) describing the relative motion and exh ibits two interesting effects: Breit-Wigner-type resonances at very lo w k(r) values, and intense glory oscillations over a large range of k( r) values. A recent experiment has measured this index of refraction, and our calculation using a very accurate sodium-argon potential and t aking into account the thermal motion of argon, agrees quite well with the experimental result.