Quantumdefect theory for the study of hadronic atoms

Abstract

Quantum defect theory can be used to convert energy shifts of hadronicatoms into zero-energy scattering lengths (and vice versa). Thescattering lengths from quantum defect theory are in good agreement withthose derived using all-order Deser-Trueman formulae (evaluated by thesimple expedient of evaluating the left-hand side of the effective rangeexpansion exactly). Scattering lengths derived from experimental energyshifts are presented for a number of hadronic atoms.