Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Differences in $dE/dX$ for $\mu+$ and $\mu-$ and its Effect on the
  Underground Charge Ratio   Theoretical calculations predict a small fractional difference in energy loss
for $\mu^+$ and $\mu^-$ of the order of $0.15 %$ at high energies. This is
predominantly due to a $z^3$ term in an extended ionization $dE/dX$ relation,
in analogy to the Barkas effect at low energies around the Bethe-Bloch maximum.
The atmospheric muon energy spectrum is steeply falling off with approximately
$E^{-3.7}$ and thus the small difference in $dE/dX$ between $\mu^+$ and $\mu^-$
at high energies results in an amplified charge asymmetry of about $0.6 %$ many
thousand meters water equivalent deep underground.

7
The categories of this paper are: hep-th
15
The categories of this paper are: nucl-ex
20
The categories of this paper are: acc-phys
26
The categories of this paper are: bayes-an
1
The categories of this paper are: cs
33
The categories of this paper are: plasm-ph
3
The categories of this paper are: physics
28
The categories of this paper are: alg-geom
22
The categories of this paper are: chao-dyn
37
The categories of this paper are: supr-con
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The categories of this paper are: astro-ph
5
The categories of this paper are: gr-qc
25
The categories of this paper are: patt-sol
35
The categories of this paper are: mtrl-th
14
The categories of this paper are: math-ph
8
The categories of this paper are: hep-ex