Determination of the S-wave pion nucleon scattering lengths from πN, pionic hydrogen and deuteron Original Research Article

The isoscalar and isovector scattering lengths (b0,b1) are determined using a unitarized coupled channel approach based on chiral Lagrangians. For the deuterium scattering length aπ−d new significant corrections are evaluated, putting new constraints from π−d scattering on the values of (b0,b1).