Initial/final state interaction in di-jet production off nuclei

Recently claimed [1–3] anomalous nuclear broadening of the out-of-plane transverse momentum in high-pt di-jet production is analyzed in view of multiple interaction of projectile/ejectile partons in nuclear matter. A model-independent relation between A-dependence of the cross section and nuclear broadening of transverse momentum is derived. Comparison with the data shows that initial/final state interaction of partons participating in a high-pt scattering is hard as well. This is a solid argument in favor of smallness of a color neutralization radius of a hadronizing highly virtual quark.