  The probability of a projectile nucleon to traverse a target nucleus without
interaction is calculated for central Si-Cu and Si-Pb collisions. Special
attention is given to the impact parameter range which contributes to events
with large transverse energy. A fit to the data from E814 requires an effective
NN cross section of sigma_eff=54.2+-5.0mb (compared to the free space value
sigma_in=30mb) and is interpreted as one related to wounded target nucleons.
