Dispersive and absorptive corrections to the pion–deuteron scattering length

Abstract We present a parameter-free calculation of the dispersive and absorptive contributions to the pion–deuteron scattering length based on chiral perturbation theory. We show that once all diagrams contributing to leading order to this process are included, their net effect provides a small correction to the real part of the pion–deuteron scattering length. At the same time the sizable imaginary part of the pion–deuteron scattering length is reproduced accurately.