  Recently claimed \cite{dj1,dj2,FC} anomalous nuclear effects in di-jet
production are analyzed in view of multiple interaction of projectile/ejectile
partons in nuclear matter. We derive model--independent relations between
A-dependence of the cross section and nuclear broadening of transverse
momentum. Comparison with the data show that initial/final state interaction of
partons participating in hard process is hard as well. This is a solid argument
in favor of smallness of a color neutralization radius of a hadronizing highly
virtual quark.
