Chiral 2$\pi$-exchange NN-potentials: Relativistic $1/M^2$-Corrections

We calculate in baryon chiral perturbation theory the relativistic $1/M^2$-corrections to the leading order two-pion exchange diagrams. We give explicit expressions for the corresponding one-loop NN-amplitudes in momentum space. The resulting isovector central and isoscalar spin-spin and tensor NN-amplitudes involve non-static terms proportional to the squared nucleon center-of-mass momentum $p^2$. From the two-pion exchange box diagrams we obtain an isoscalar quadratic spin-orbit NN-amplitude. We give also analytical expressions for the corresponding NN-potentials in coordinate space. The diagrammatic results presented here make the chiral NN-potential complete at next-to-next-to-next-to-leading order.