Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Physical characteristics of glasma from the earliest stage of
  relativistic heavy ion collisions   We present analytic results that describe the gluon field, or glasma, at very
early times after a collision of relativistic heavy ions at proper time
$\tau=0$. We use a Colour Glass Condensate approach, and perform an expansion
in $\tau$. The full details of our method are described in our previous paper
[1]. In this paper we present an analysis of various physical quantities that
can be obtained from the energy-momentum tensor. We show that the expansion to
order $\tau^6$ can be trusted to about $\tau=0.05$ fm. For times small enough
that the expansion converges, the transverse and longitudinal pressures move
towards their equilibrium values of one third of the energy density. The
Fourier coefficients of the azimuthal flow are larger than expected, which
contradicts the usual assumption that anisotropy is mostly generated during the
hydrodynamic evolution of the plasma. We find a significant correlation between
the elliptic flow coefficient and the eccentricity, which indicates that the
spatial asymmetry introduced by the initial geometry is effectively transmitted
to the azimuthal distribution of the gluon momentum field, even at very early
times. This result is interesting because correlations of this kind are
characteristic of the onset of hydrodynamic behaviour. We show that the angular
momentum of the glasma is orders of magnitude smaller than the angular momentum
of the initial system of ions colliding with non-zero impact parameter. This
indicates that most of the angular momentum carried by the valence quarks is
not transmitted to the glasma, and contradicts the picture of a rapidly
rotating initial glasma state that has been proposed by several authors, but
agrees with the current lack of experimental evidence for a significant
polarization effect of the hyperons and vector mesons produced in heavy ion
collisions at the highest accessible energies.

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The categories of this paper are: cond-mat
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The categories of this paper are: acc-phys
15
The categories of this paper are: nucl-ex
19
The categories of this paper are: eess
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The categories of this paper are: physics
35
The categories of this paper are: mtrl-th
13
The categories of this paper are: quant-ph
21
The categories of this paper are: adap-org
32
The categories of this paper are: atom-ph
30
The categories of this paper are: q-alg
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The categories of this paper are: q-bio
33
The categories of this paper are: plasm-ph
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The categories of this paper are: stat
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The categories of this paper are: math
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The categories of this paper are: solv-int
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The categories of this paper are: cmp-lg