On rescattering effects in the reaction π-d → π-d

Rescattering corrections to the impulse approximation for the processes gammad --> pi(0)d and pi(-)d --> pi(-)d are discussed. It is shown that the rescattering effects give a nonnegligible contribution to the real part of these amplitudes. At the same time, the contributions from the imaginary parts of impulse and rescattering corrections drastically cancel each other. This cancellation means that the processes pi(-)d --> pi(0)nn and gammad --> n(+)nn/pi(-)pp, when the nucleon pair is in the spin triplet state, are strongly suppressed near threshold as required by the Pauli principle. (C) 2004 MAIK "Nauka/Interperiodica".