Time Evolution of Hadronization and Grey Tracks in DIS off Nuclei
  The analysis of the grey tracks produced in Deep Inelastic Scattering (DIS) off nuclei provides important information on the space-time development of hadronization in nuclear medium. This method is complementary to the measurement of nuclear attenuation of leading inclusive hadrons. While the latter is focused on the hadronization dynamics for the quite rare process of leading hadrons production, the former covers the main bulk of inelastic events, and its Q^2 dependence is a very sensitive tool to discriminate between different models of hadronization. Employing the model of perturbative hadronization developed earlier, we calculate the Q^2 and x_{Bj} dependences of the number of collisions and relate it to the mean number of grey tracks, using an empirical relation obtained from the analysis of data from the Fermilab E665 experiment on DIS of muons off the Xe nucleus. We found the number of grey tracks to rise steeply with Q^2 in good agreement with the experimental data. 
C. Ciofi degli Atti and B.Z. Kopeliovich