The cumulative process is particle production in a kinematical region forbidden for reactions with free nucleons. The SPIN set up  provides a detailed study of  charged particles emitted with high transverse momentum ( p_T > 1 GeV/c) from nuclear targets irradiated with protons from the U70 accelerator of the Institute for High Energy Physics. The working kinematic region of the SPIN experiment makes it possible to study the cumulative particle production caused by hard interactions with dense multiquark (multinucleon)  configurations  inside nuclear matter. Cross-sections for the antiproton production as a function of momentum are presented in the left figure for four targets, C, Al, Cu and W. The upper horizontal axis shows the X₂ values (“Stavinsky variable” [1]), which corresponds to the minimum target mass required to produce antiprotons at an angle of 40⁰. The curves in the left figure are calculations in accordance with the parameterization [2], in which the dependence of the cross sections on the  nuclear mass (A) is represented by ~$A^{(2.4+X_2)/3}$. Close to universal for all targets  X₂-dependence is an evidence for formation of antiprotons in interactions with  multinucleon (multiquark) configurations inside a nucleus.