Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Measurement of the atmospheric muon flux with the NEMO Phase-1 detector   The NEMO Collaboration installed and operated an underwater detector
including prototypes of the critical elements of a possible underwater km3
neutrino telescope: a four-floor tower (called Mini-Tower) and a Junction Box.
The detector was developed to test some of the main systems of the km3
detector, including the data transmission, the power distribution, the timing
calibration and the acoustic positioning systems as well as to verify the
capabilities of a single tridimensional detection structure to reconstruct muon
tracks. We present results of the analysis of the data collected with the NEMO
Mini-Tower. The position of photomultiplier tubes (PMTs) is determined through
the acoustic position system. Signals detected with PMTs are used to
reconstruct the tracks of atmospheric muons. The angular distribution of
atmospheric muons was measured and results compared with Monte Carlo
simulations.

30
The categories of this paper are: q-alg
4
The categories of this paper are: cond-mat
22
The categories of this paper are: chao-dyn
3
The categories of this paper are: physics
31
The categories of this paper are: ao-sci
9
The categories of this paper are: nlin
34
The categories of this paper are: chem-ph
26
The categories of this paper are: bayes-an
17
The categories of this paper are: q-fin
32
The categories of this paper are: atom-ph
0
The categories of this paper are: hep-ph
27
The categories of this paper are: comp-gas
16
The categories of this paper are: stat
2
The categories of this paper are: math
35
The categories of this paper are: mtrl-th
28
The categories of this paper are: alg-geom