Spectra of fast π + mesons from the π − A → π + X reaction on oxygen and lithium nuclei at 0.59 GeV

The spectra of fast π ⁺ mesons from the π ^? A → π ⁺ X reaction on A=⁶Li, ⁷Li, and ¹⁶O nuclei at a primary momentum of p ₀=0.72 GeV/c (T ₀=0.59 GeV) are measured at emission-angle values in the range ?=0°–14°. The results obtained in this way are compared with experimental data taken in other studies at lower energies and with the results of model calculations. The energy dependence of the cross sections and of shadowing effects is analyzed for the reactions in question that occur on lithium isotopes.