Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Elliptic flow and the symmetry energy at supra-saturation density   The elliptic flow in collisions of neutron-rich heavy-ion systems at
intermediate energies emerges as an observable sensitive to the strength of the
symmetry energy at supra-saturation densities. First results obtained by
comparing ratios or differences of neutron and hydrogen flows with predictions
of transport models favor a moderately soft to linear density dependence,
consistent with ab-initio nuclear-matter theories. Comprehensive data sets of
high accuracy can be expected to improve our knowledge of the equation of state
of asymmetric nuclear matter.

3
The categories of this paper are: physics
35
The categories of this paper are: mtrl-th
14
The categories of this paper are: math-ph
9
The categories of this paper are: nlin
2
The categories of this paper are: math
29
The categories of this paper are: funct-an
20
The categories of this paper are: acc-phys
21
The categories of this paper are: adap-org
24
The categories of this paper are: dg-ga
25
The categories of this paper are: patt-sol
4
The categories of this paper are: cond-mat
28
The categories of this paper are: alg-geom
7
The categories of this paper are: hep-th
33
The categories of this paper are: plasm-ph
23
The categories of this paper are: solv-int
34
The categories of this paper are: chem-ph