Speaker
Prof.
Yasushi Nara
(Akita International University)
Description
Yes, it does! We investigate the effects of nuclear mean-field on the directed flow
$v_1$ in high energy nucleus-nucleus collisions
from $\sqrt{s_{NN}}=2.7$ GeV to 27 GeV incident energies
within a transport theoretical model based on the framework of
the relativistic quantum molecular dynamics.
Specifically, we use the JAM transport model with potentials.
Our approach reproduces the rapidity dependence of directed flow data up to
$\sqrt{s_{NN}}\approx 9$ GeV showing the significant importance of mean-field.
However, the slopes of $dv_1/dy$ at mid-rapidity are positive
at $\sqrt{s_{NN}}=11.7$ and 19.6 GeV, and becomes negative above 27 GeV.
Thus the result from a JAM hadronic transport model with nuclear mean-field approach is incompatible with the data.
Therefore within our approach, we conclude that the excitation function of
the directed flow cannot be explained by the hadronic degree of freedom alone.
| On behalf of collaboration: | NONE |
|---|
Author
Prof.
Yasushi Nara
(Akita International University)
Co-author
Akira Ohnishi
(Kyoto University)
