Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Iron Air collision with high density QCD   The color glass condensate approach describes successfully heavy ion
collisions at RHIC. We investigate Iron-air collisions within this approach and
compare results to event generators commonly used in air shower simulations. We
estimate uncertainties in the extrapolation to GZK energies and discuss
implications for air shower simulations.

18
The categories of this paper are: econ
1
The categories of this paper are: cs
23
The categories of this paper are: solv-int
4
The categories of this paper are: cond-mat
3
The categories of this paper are: physics
12
The categories of this paper are: nucl-th
24
The categories of this paper are: dg-ga
33
The categories of this paper are: plasm-ph
30
The categories of this paper are: q-alg
29
The categories of this paper are: funct-an
25
The categories of this paper are: patt-sol
31
The categories of this paper are: ao-sci
16
The categories of this paper are: stat
34
The categories of this paper are: chem-ph
26
The categories of this paper are: bayes-an
28
The categories of this paper are: alg-geom