“…. Special features of this method in the case of the production of two jets were considered in detail in [2][3][4][5]. In that case, secondary particles refer to the region of target (beam) fragmentation if X k t ≥ (≤)X bnd X k b ≤ (≥)X bnd , where X k p = [m k (U k U r )][m p (U p U r )] −1 , p, r = t, b; p = r; m k is the mass of the kth secondary particle; m t/b is the mass of the target/beam particles; U k = P k /m k is the 4-velocity; k = t, b, 1, 2, .…”