  The influence of Coulomb interaction on the phenomenon of "optical" spin
rotation of negatively charged particles (antiprotons, etc.) moving in matter
with polarized nuclei is considered. It is shown that because the density of
the antiproton (negative hyperon) wave function on the nucleus increases, the
spin precession frequency grows as the particle decelerates. As a result, spin
rotation of negatively charged particles becomes observable despite their rapid
deceleration. This provides information about the spin--dependent part of the
amplitude of coherent elastic zero--angle scattering in the range of low
energies, where scattering experiments are practically impossible to perform.
