Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Directed flow at midrapidity in heavy-ion collisions   It was recently shown that fluctuations in the initial geometry of a heavy
ion collision generally result in a dipole asymmetry of the distribution of
outgoing particles. This asymmetry, unlike the usual directed flow, is expected
to be present at a wide range of rapidity -- including midrapidity. First
evidence of this phenomenon can be seen in recent two-particle correlation data
by STAR, providing the last element necessary to quantitatively describe
long-range dihadron correlations. We extract differential directed flow from
these data and propose a new direct measurement.

36
The categories of this paper are: cmp-lg
28
The categories of this paper are: alg-geom
33
The categories of this paper are: plasm-ph
1
The categories of this paper are: cs
2
The categories of this paper are: math
31
The categories of this paper are: ao-sci
24
The categories of this paper are: dg-ga
34
The categories of this paper are: chem-ph
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The categories of this paper are: acc-phys
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The categories of this paper are: astro-ph
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The categories of this paper are: patt-sol
3
The categories of this paper are: physics
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The categories of this paper are: econ
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The categories of this paper are: bayes-an
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The categories of this paper are: q-alg
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The categories of this paper are: q-fin