Strong interaction effects in kaonic deuterium

High precision measurements of kaonic hydrogen x rays and also, for the first time, of kaonic deuterium are under way within the DEAR project using the e(+)e(-) storage ring at Frascati. The values of the strong interaction Is level shift and width in kaonic deuterium cannot be simply predicted by relating them, via the Deser-Trueman formula. to the K- d scattering length because the latter is not known experimentally: it cannot be obtained by adding the K- p and K- n scattering lengths but involves the solution of a complicated multichannel three-body problem. We give results of calculations of the kaonic deuterium strong interaction shift and width using an (N (K) over bar, Y pi) interaction (Y = Lambda,Sigma) that fits the available low-energy scattering data. The 1 s level shift in kaonic deuterium comes out negative and both the shift and the width are estimated to be about 1 keV. The 2p capture rate is estimated to be smaller than the 2p --> 1s x-ray transition rate. This information is of importance for the planned experiment as it indicates that most of the kaons should reach the lowest Is level. [S0556-2813(99)02307-9].