  We show that the distributions of outgoing protons and charged hadrons in
high energy proton-nucleus collisions are described rather well by a linear
extrapolation from proton-proton collisions. The only adjustable parameter
required is the shift in rapidity of a produced charged meson when it
encounters a target nucleon. Its fitted value is 0.16. Next, we apply this
linear extrapolation to precisely measured Drell-Yan cross sections for 800 GeV
protons incident on a variety of nuclear targets which exhibit a deviation from
linear scaling in the atomic number A. We show that this deviation can be
accounted for by energy degradation of the proton as it passes through the
nucleus if account is taken of the time delay of particle production due to
quantum coherence. We infer an average proper coherence time of 0.4 +/- 0.1
fm/c, corresponding to a coherence path length of 8 +/- 2 fm in the rest frame
of the nucleus. Finally, we apply the linear extrapolation to measured J/Psi
production cross sections for 200 and 450 GeV/c protons incident on a variety
of nuclear targets. Our analysis takes into account energy loss of the beam
proton, the time delay of particle production due to quantum coherence, and
absorption of the J/Psi on nucleons. The best representation is obtained for a
coherence time of 0.5 fm/c, which is consistent with Drell-Yan production, and
an absorption cross section of 3.6 mb, which is consistent with the value
deduced from photoproduction of the J/Psi on nuclear targets.
