Three-body calculation of the $1s$ level shift in kaonic deuterium with realistic $\bar{K}N$ potentials

摘要

The $1s$ level shift in kaonic deuterium was calculated using CoulombSturmian expansion of Faddeev equations. The convergence of the method yieldsan $\sim\ 1\ eV$ accuracy for the level shifts. We used three different,realistic, multichannel $\bar{K}N$ interactions reproducing all knownexperimental two-body $\bar{K}N$ data. The different results suggest, that thelevel shift should be in the range $\Delta E\sim(800\pm30)-(480\pm20){\rm i}\ \eV$. The (almost) exact level shifts were compared with values, given by thecommonly used approximations.