Kaon-nucleon scattering lengths from kaonic deuterium experiments revisited

We analyse the impact of the recent measurement of kaonic hydrogen X rays by the SIDDHARTA collaboration on the allowed ranges for the kaon-deuteron scattering length in the framework of non-relativistic effective field theory. Based on data from K¯N scattering only, we predict the kaon-deuteron scattering length AKd=(−1.46+i1.08) fm, with an estimated uncertainty of about 25% in both the real and the imaginary part.