Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Results from the GAMMA experiment on Mt. Aragats   The present status of the GAMMA facility consisting of an enlarged surface
EAS array (116 of 1 m^2 scintillation detectors) and underground muon carpet
(150 m^2 detectors) is described. The recent results on mass composition and
energy spectrum at the energy region above the knee obtained on the basis of
the GAMMA experimental data are presented. It is shown that the power law after
the knee is not invariable like -3.1. The slope of the energy spectrum becomes
more flat at E0>20 PeV. The strong irregularities of the energy spectrum at
about 70-80 PeV are discussed in comparison with other experiments. The bump
can be described by a two-component model of primary cosmic ray origin, where
additional (pulsar) Fe components are included with a very flat power law
energy spectrum.

35
The categories of this paper are: mtrl-th
24
The categories of this paper are: dg-ga
23
The categories of this paper are: solv-int
17
The categories of this paper are: q-fin
1
The categories of this paper are: cs
16
The categories of this paper are: stat
14
The categories of this paper are: math-ph
31
The categories of this paper are: ao-sci
22
The categories of this paper are: chao-dyn
27
The categories of this paper are: comp-gas
19
The categories of this paper are: eess
9
The categories of this paper are: nlin
0
The categories of this paper are: hep-ph
7
The categories of this paper are: hep-th
3
The categories of this paper are: physics
32
The categories of this paper are: atom-ph