Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Study of muons from ultra-high energy cosmic ray air showers measured
  with the Telescope Array experiment   One of the uncertainties in interpretation of ultra-high energy cosmic ray
(UHECR) data comes from the hadronic interaction models used for air shower
Monte Carlo (MC) simulations. The number of muons observed at the ground from
UHECR-induced air showers is expected to depend upon the hadronic interaction
model. One may therefore test the hadronic interaction models by comparing the
measured number of muons with the MC prediction. In this paper, we present the
results of studies of muon densities in UHE extensive air showers obtained by
analyzing the signal of surface detector stations which should have high
$\it{muon \, purity}$. The muon purity of a station will depend on both the
inclination of the shower and the relative position of the station. In 7 years'
data from the Telescope Array experiment, we find that the number of particles
observed for signals with an expected muon purity of $\sim$65% at a lateral
distance of 2000 m from the shower core is $1.72 \pm 0.10{\rm (stat.)} \pm 0.37
{\rm (syst.)}$ times larger than the MC prediction value using the QGSJET II-03
model for proton-induced showers. A similar effect is also seen in comparisons
with other hadronic models such as QGSJET II-04, which shows a $1.67 \pm 0.10
\pm 0.36$ excess. We also studied the dependence of these excesses on lateral
distances and found a slower decrease of the lateral distribution of muons in
the data as compared to the MC, causing larger discrepancy at larger lateral
distances.

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The categories of this paper are: q-fin
12
The categories of this paper are: nucl-th
37
The categories of this paper are: supr-con
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The categories of this paper are: econ
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The categories of this paper are: alg-geom
30
The categories of this paper are: q-alg
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The categories of this paper are: funct-an
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The categories of this paper are: patt-sol
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The categories of this paper are: nlin
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The categories of this paper are: bayes-an
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The categories of this paper are: solv-int
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The categories of this paper are: cmp-lg
1
The categories of this paper are: cs
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The categories of this paper are: hep-lat
5
The categories of this paper are: gr-qc
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The categories of this paper are: plasm-ph