Charge transfer and elastic scattering in very slow H++D(1s) half collisions

Charge transfer and elastic scattering probabilities were measured for half collisions between very slow protons and atomic deuterium. Collision energ ies down to a few meV, lower by more than an order of magnitude and with be tter energy resolution than previous measurements, were studied using the d issociation of the HD+ electronic ground state. The collision energy is det ermined a posteriori from the measured momentum vector of the dissociating charged fragments. The experimental results are in good agreement with our coupled channel calculations.