Bjorken-x dependence of many-body correlations in DIS cross section ratios off nuclei

Many-body correlations in nuclei determine the behavior of Deep-Inelastic-Scattering (DIS) cross section ratios off heavy over light nuclei especially for Bjorken-x $>$ 1, obtained at Jefferson Laboratory. Such correlations can be described in terms of quark-cluster formation in nuclei due to wave-function overlapping. In clusters (correlated nucleons) the quark and gluon momentum distributions are softer than in single nucleons and extend to x $>$ 1. The probabilities for such clusters are computed using a network-defining algorithm in which the initial nucleon density is either standard Woods-Saxon or is input from lower energy data while the critical radius for nucleon merging is an adjustable parameter. The exact choice of critical radius depends on the specific nucleus and it is anti-correlated to the rescaling of the Bjorken-x for bound nucleons. The calculations show that there is a strong dependence of the cross section ratios on Bjorken-x in agreement with the data and that four-body correlations are needed to explain the experimental results even in the range 2 $<$ Bjorken-x $<$ 3.