11 Influence of the Neutron Skin of Nuclei on Observables
143
Fig. 11.4 Impact parameter dependence of the ratio π − /π + in collisions of Au(400 AMeV)+Au.
Left: influence of the equation of state of asymmetric matter, right: influence of neutron skin and
delta Pauli blocking
for protons and neutrons using calculations with and without neutron skin. In the
following figures we will mark protons with red full lines when using R P = R N and
with blue dashed lines for R P < R N . Neutrons are presented by magenta dasheddotted lines for R P = R N and by cyan dotted lines for R P < R N .
11.3.1 Observables Related to Stopping on Transverse
Pressure
Let us first look on the rapidity distribution of protons and neutrons in a semiperipheral reaction of Au+Au at 400 AMeV incident energy. Figure 11.5 shows on the
left-hand side the rapidity distribution of protons and neutrons. Up to the difference
of absolute numbers there is no significant effect. The right-hand side presents the
transverse energy ratio E rat = E trans /E long for protons and neutrons. An isotropic
system would yield a value of 2, higher values correspond to the dominance of
the transverse direction, lower to the dominance of the longitudinal direction, e.g.,
for incomplete stopping. We see very similar behavior for protons and neutrons,
independently of the use of the neutrons skin. Similarly the transverse momentum
distribution d N/ p T dp T at central rapidity shown on the left-hand side Fig. 11.6 is
very similar for all cases. Also the mean transverse momentum show no significance.
Only for very peripheral systems there seems to be a slight enhancement for neutrons,
independent of the choice on the neutron skin.
143
Fig. 11.4 Impact parameter dependence of the ratio π − /π + in collisions of Au(400 AMeV)+Au.
Left: influence of the equation of state of asymmetric matter, right: influence of neutron skin and
delta Pauli blocking
for protons and neutrons using calculations with and without neutron skin. In the
following figures we will mark protons with red full lines when using R P = R N and
with blue dashed lines for R P < R N . Neutrons are presented by magenta dasheddotted lines for R P = R N and by cyan dotted lines for R P < R N .
11.3.1 Observables Related to Stopping on Transverse
Pressure
Let us first look on the rapidity distribution of protons and neutrons in a semiperipheral reaction of Au+Au at 400 AMeV incident energy. Figure 11.5 shows on the
left-hand side the rapidity distribution of protons and neutrons. Up to the difference
of absolute numbers there is no significant effect. The right-hand side presents the
transverse energy ratio E rat = E trans /E long for protons and neutrons. An isotropic
system would yield a value of 2, higher values correspond to the dominance of
the transverse direction, lower to the dominance of the longitudinal direction, e.g.,
for incomplete stopping. We see very similar behavior for protons and neutrons,
independently of the use of the neutrons skin. Similarly the transverse momentum
distribution d N/ p T dp T at central rapidity shown on the left-hand side Fig. 11.6 is
very similar for all cases. Also the mean transverse momentum show no significance.
Only for very peripheral systems there seems to be a slight enhancement for neutrons,
independent of the choice on the neutron skin.