Some recent studies of nuclear production processes depend critically on $\overline{\nu }$, an average number of inelastic collisions that energetic projectiles experience inside nuclei. We discuss properties and values of $\overline{\nu }$ to answer some questions rising out of recent work and facilitate comparison of the theories with experimental data.

• Received 18 November 1974

DOI:https://doi.org/10.1103/PhysRevLett.34.622