Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Classical model for diffusion and thermalization of heavy quarks in a
  hot medium: memory and out-of-equilibrium effects   We consider a simple model for the diffusion of heavy quarks in a hot bath,
modeling the latter by an ensemble of oscillators distributed accorded to
either a thermal distribution or to an out-of-equilibrium distribution with a
saturation scale. Within this model it is easy to introduce memory effects by
changing the distribution of oscillators: we model these by introducing a
gaussian distribution, $dN/d\omega$, which can be deformed continuously from a
$\delta-$function giving a Markov dissipation to a broad kernel with memory.
Deriving the equation of motion of the heavy quark in the bath we remark how
dissipation comes out naturally as an effect of the back-reaction on the bath
of oscillators. Moreover, the exact solution of this equation allows for the
definition of a thermalization time as the time necessary to remove any memory
of the initial condition. We find that the broadening the dissipative kernel
while keeping the coupling fixed lowers the thermalization time. We also derive
the fluctuation-dissipation theorem for the bath, and use this to estimate the
kinematic regime in which momentum diffusion of the heavy quark dominates over
drift: we find that diffusion is more important as long as $K_0/{\cal E}$ is
small, where $K_0$ and ${\cal E}$ denote the initial energy of the heavy quark
and the average energy of the bath respectively.

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The categories of this paper are: dg-ga
33
The categories of this paper are: plasm-ph
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The categories of this paper are: solv-int
9
The categories of this paper are: nlin
5
The categories of this paper are: gr-qc
34
The categories of this paper are: chem-ph
2
The categories of this paper are: math
16
The categories of this paper are: stat
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The categories of this paper are: cmp-lg
13
The categories of this paper are: quant-ph
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The categories of this paper are: ao-sci
32
The categories of this paper are: atom-ph
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The categories of this paper are: eess
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The categories of this paper are: patt-sol
0
The categories of this paper are: hep-ph
17
The categories of this paper are: q-fin