Dispersive and absorptive corrections to the pion-deuteron scattering   length
  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. 
V. Lensky, V. Baru, J. Haidenbauer, C. Hanhart, A. Kudryavtsev, and   U.-G. Mei{\ss}ner