Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Lorentz invariant relative velocity and relativistic binary collisions   This article reviews the concept of Lorentz invariant relative velocity that
is often misunderstood or unknown in high energy physics literature. The
properties of the relative velocity allow to formulate the invariant flux and
cross section without recurring to non--physical velocities or any assumption
about the reference frame. Applications such as the luminosity of a collider,
the use as kinematic variable, and the statistical theory of collisions in a
relativistic classical gas are reviewed. It is emphasized how the hyperbolic
properties of the velocity space explain the peculiarities of relativistic
scattering.

21
The categories of this paper are: adap-org
1
The categories of this paper are: cs
13
The categories of this paper are: quant-ph
15
The categories of this paper are: nucl-ex
37
The categories of this paper are: supr-con
28
The categories of this paper are: alg-geom
12
The categories of this paper are: nucl-th
10
The categories of this paper are: q-bio
27
The categories of this paper are: comp-gas
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The categories of this paper are: stat
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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
5
The categories of this paper are: gr-qc
36
The categories of this paper are: cmp-lg
9
The categories of this paper are: nlin