Kaon-nucleon scattering lengths from kaonic deuterium experiments

The extraction of the S-wave kaon-nucleon scattering lengths a(0) and a(1) from a combined analysis of existing kaonic hydrogen and synthetic deuterium data has been carried out within the framework of a low-energy effective field theory. It turns out that with the present DEAR central values for the kaonic hydrogen ground-state energy and width, a solution for a(0) and a(1) exists only in a restricted domain of input values for the kaon-deuteron scattering length. Consequently, measuring this scattering length imposes stringent constraints on the theoretical description of the kaon-deuteron interactions at low energies, if supplemented with DEAR data on kaonic hydrogen.