“…The experimental data show a rise of the π − /π + ratio with the decrease of the π meson momentum in a good agreement with the prediction of the BC model and to a lesser extent with the INCL model prediction. This increase can be associated with the so-called "spectator" effect, for the first time observed in the experiments at the LBL in Berkeley [30,31] in the fragmentation of light ions at 0 • at energies of several hundred MeV/nucleon and later seen in the NA49 and NA61/SHINE experiments at the SPS CERN in peripheral collisions of lead ions at 150 GeV/nucleon and small (≤100 MeV/c) π meson transverse momenta (for a review of these data, see [32]). A theoretical explanation of this effect was given in [33] back in 1982, but the processes, associated with this Coulomb effect in interactions of relativistic heavy ions, are widely discussed at the present time (see, e.g., [34]).…”