The method of extracting excitation energy for the ISiS data is described in T.Lefort et al, Phys. Rev. C, 64, 064603 (2001).

Figure (mader-BUU) : Projectile energy dissipation in p + A reactions results from both N-N scattering and the excitation of nucleonic resonances followed by reabsorbtion of the decay pions. This process occurs on a very fast time scale, of order ten fm/c. Shown in the figure are the time-integrated trajectories of the deltas (blue) and pions (red) for the reaction of a 5 GeV proton with lead.

Figure (xyz0): Figure shows the time-evolution of a central collision (b = 2 fm)involving a 14.6 GeV proton on a gold nucleus. The fast cascade process leaves the residue in a state of depleted density throughout all but the earliest stages of the interaction. THIS IS THE PRIMARY DIFFERENCE BETWEEN p + A and A + A REACTIONS; i.e. there is minimal compression and the randomized residue in central collisions develops from an initial state of less than normal density.

Figure (BUU-2): Calculations with the Danielewicz BUU code, which includes A = 2 and 3 clusters, a momentum-dependent potential and reduced in-medium cross sections. The latter two conditions give the best description of the A = 1-3 isotope ratios and the excitation energy distribution. Plots are shown for the time evolution of the residue density, E*/A, entropy/nulcleon and mass loss. The calculations indicate that AFTER A COLLISION TIME OF ABOUT 30 - 40 FM/C, THE RESIDUE APPEARS TO BE RANDOMIZED.

Bottom Line: In GeV p and A reactions:

(1) Energy deposition is continuous but less than 20% of projective energy at most,

(2) Energy deposition is very fast, fm/c(3) Residue is randomized after ~ 30 fm/c(4) Residue is created in a state of depleted density.

Figure (mader-BUU) : Projectile energy dissipation in p + A reactions results from both N-N scattering and the excitation of nucleonic resonances followed by reabsorbtion of the decay pions. This process occurs on a very fast time scale, of order ten fm/c. Shown in the figure are the time-integrated trajectories of the deltas (blue) and pions (red) for the reaction of a 5 GeV proton with lead.

Figure (xyz0): Figure shows the time-evolution of a central collision (b = 2 fm) involving a 14.6 GeV proton on a gold nucleus. The fast cascade process leaves the residue in a state of depleted density throughout all but the earliest stages of the interaction. THIS IS THE PRIMARY DIFFERENCE BETWEEN p + A and A + A REACTIONS; i.e. there is minimal compression and the randomized residue in central collisions develops from an initial state of less than normal density.

Figure (BUU-2): Calculations with the Danielewicz BUU code, which includes A = 2 and 3 clusters, a momentum-dependent potential and reduced in-medium cross sections. The latter two conditions give the best description of the A = 1-3 isotope ratios and the excitation energy distribution. Plots are shown for the time evolution of the residue density, E*/A, entropy/nulcleon and mass loss. The calculations indicate that AFTER A COLLISION TIME OF ABOUT 30 - 40 FM/C, THE RESIDUE APPEARS TO BE RANDOMIZED.