Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Scaling violation in interaction of cosmic ray hadrons and the nature of
  the 3 PeV knee in the spectrum of primary cosmic rays   Energy spectra of the most energetic hadrons in the core region of extensive
air showers (EAS) were studied in dependence on the EAS energy $E_0$ in the
hybrid experiment HADRON at the Tien Shan mountain cosmic ray station. For the
first time by direct measurement it was found in this experiment that the slope
of the power energy spectrum of EAS hadrons diminishes itself locally, and the
average hadron energy, correspondingly, increases between the $E_0$ borders
3PeV and 20PeV. Such behavior agrees with threshold appearance in EAS, in the
same energy range, of a long-flying penetrative component which was earlier
revealed at the Tien Shan station. Now we reconsider this Tien Shan result in
comparison with the new data of modern collider experiments. The analysis
permits to state unambiguously an astrophysical nature of the penetrative EAS
component, and to discuss its probable connection with the origin of the famous
knee in the energy spectrum of cosmic rays at $E_0\simeq 3$ PeV.

34
The categories of this paper are: chem-ph
33
The categories of this paper are: plasm-ph
2
The categories of this paper are: math
23
The categories of this paper are: solv-int
1
The categories of this paper are: cs
32
The categories of this paper are: atom-ph
27
The categories of this paper are: comp-gas
11
The categories of this paper are: hep-lat
28
The categories of this paper are: alg-geom
37
The categories of this paper are: supr-con
16
The categories of this paper are: stat
31
The categories of this paper are: ao-sci
0
The categories of this paper are: hep-ph
7
The categories of this paper are: hep-th
10
The categories of this paper are: q-bio
22
The categories of this paper are: chao-dyn