Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Interpretation of the Underground Muon Charge Ratio   The MINOS experiment has observed a rise in the underground muon charge ratio
$r_\mu$ = ${\mu^+/\mu^-}$. This ratio can be related to the atmospheric
production ratios of ${\pi^+/\pi^-}$ and ${K^+/K^-}$. Our analysis indicates
that the relevant variable for studying the charge ratio+ $\ecos$, rather than
$\emu$. We compare a simple energy dependent parameterization of the rise in
the charge ratio with more detailed previously published Monte Carlo
simulations and an analytical calculation. We also estimate the size of two
previously neglected effects in this context: the charge sign dependency of the
dE/dx in rock, and the energy dependence of heavy primaries on the derived
${K^+/K^-}$ ratio.

32
The categories of this paper are: atom-ph
25
The categories of this paper are: patt-sol
36
The categories of this paper are: cmp-lg
20
The categories of this paper are: acc-phys
37
The categories of this paper are: supr-con
2
The categories of this paper are: math
22
The categories of this paper are: chao-dyn
18
The categories of this paper are: econ
24
The categories of this paper are: dg-ga
14
The categories of this paper are: math-ph
15
The categories of this paper are: nucl-ex
13
The categories of this paper are: quant-ph
16
The categories of this paper are: stat
34
The categories of this paper are: chem-ph
21
The categories of this paper are: adap-org
3
The categories of this paper are: physics