Nix-Chapman produces roughly equal freezeout temperatures at AGS and SPS
enegies, as did the study on systematics of the slopes. However, the N-C value
is considerably lower (~100 vs. ~140).
At any particular time slice, N-C produces particles only from the
hypersurface. However, when you ask RQMD at any particular time what the
origin is of pions that will no longer interact, it shows that they come from
throughout the volume, and are peaked in the center.
It would be nice if his surface-vs-volume production issue could be resolved.
The reason for the tendency of N-C to produce lambdas lower than 1.0
needs to be investigated.
John Sullivan and I are working with members of the T8 theory group (Ray
Nix, Bernd Schlei, Dan Strottmann) to elucidate some of these points, and to
improve on the preliminary NA44 fits.
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