ACCURATE EVALUATION OF WAVE FUNCTIONS OF PIONIUM AND KAONIUM

Abstract

Pionium and kaonium are studied in an accurate numerical approach based on Sturmian functions. It is found that the ground-state wave functions of the exotic atoms in realistic strong interactions, particularly for kaonium, are considerably different from the hydrogen-like ones at small distances. The kaon-kaon scattering length derived from the 1s energy shift of kaonium by applying the Deser-Trueman formula is strongly inconsistent with the one derived directly by solving the Schödinger equation. The theoretical results indicate that it is arguable to treat kaonium perturbatively.