Presentation is loading. Please wait.

Presentation is loading. Please wait.

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.

Similar presentations


Presentation on theme: "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."— Presentation transcript:

1 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.

2 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.

3 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.

4 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.


Download ppt "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."

Similar presentations


Ads by Google