Improved constraints on chiral SU(3) dynamics from kaonic hydrogen

A new improved study of K−-proton interactions near threshold is performed using coupled-channels dynamics based on the next-to-leading order chiral SU(3) meson-baryon effective Lagrangian. Accurate constraints are now provided by new high-precision kaonic hydrogen measurements. Together with threshold branching ratios and scattering data, these constraints permit an updated analysis of the complex K¯N and πΣ coupled-channels amplitudes and an improved determination of the K−p scattering length, including uncertainty estimates.