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C. Hartnack et al.
Fig. 11.5 Stopping in Au(400 AMeV)+Au. Left: rapidity distribution for b = 6 fm, right: centrality
dependence of E rat = E trans /E long
Fig. 11.6 Transverse momentum in Au(400 AMeV)+Au. Left: Transverse momentum distribution
for b = 6 fm, right: Mean value of the transverse momentum as a function of centrality
11.3.2 Observables Related to Transverse and Elliptic Flow
Next let us focalize on directed flow of protons and neutrons. From the left-hand side
of Fig. 11.7 we see that in calculations without neutron skin (R P = R N ) we yield
slightly higher flow in semiperipheral collisions, an effect that can also be seen in
the centrality dependence of the directed flow parameter v 1 at the right-hand side.
However, the effects are quite small. Similarly it seems that the elliptic flow is a
bit stronger negative without neutron skin. Even if this can hardly be seen in the
azimuthal distribution on the left-hand side of Fig. 11.8 the centrality dependence
of v 2 on the right-hand side shows some indication of this effect for semiperipheral
collisions.