Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Novel rapidity dependence of directed flow in high energy heavy ion
  collisions   For high energy nucleus-nucleus collisions, we show that a combination of
space-momentum correlations characteristic of radial expansion together with
the correlation between the position of a nucleon in the nucleus and its
stopping, results in a very specific rapidity dependence of directed flow: a
reversal of sign in the mid-rapidity region. We support our argument by RQMD
model calculations for Au+Au collisions at $\sqrt s$ = 200 AGeV.

3
The categories of this paper are: physics
35
The categories of this paper are: mtrl-th
11
The categories of this paper are: hep-lat
37
The categories of this paper are: supr-con
17
The categories of this paper are: q-fin
16
The categories of this paper are: stat
36
The categories of this paper are: cmp-lg
5
The categories of this paper are: gr-qc
0
The categories of this paper are: hep-ph
2
The categories of this paper are: math
34
The categories of this paper are: chem-ph
27
The categories of this paper are: comp-gas
29
The categories of this paper are: funct-an
8
The categories of this paper are: hep-ex
24
The categories of this paper are: dg-ga
9
The categories of this paper are: nlin