Growth of nuclear spin precession frequency of antiprotons (negative hyperons) under deceleration in matter with polarized nuclei

The Coulomb interaction leads to an increase of the real part of the amplitude of scattering of negatively charged particles (antiprotons, hyperons) by nuclei. In consequence, when antiprotons (negative hyperons) are decelerated in a medium with polarized nuclei, their effective energy of interaction with the medium and the nuclear spin precession frequency in a pseudomagnetic field grow as the particles decelerate. 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.