Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Precision Measurement of the Proton Flux in Primary Cosmic Rays from 1
  GV to 1.8 TV with the Alpha Magnetic Spectrometer on the International Space
  Station   A precision measurement of the proton flux in primary cosmic rays with
rigidity from 1 GV to 1.8 TV is presented based on 300 million events. The
results show that the proton flux is smooth and exhibits no sharp structures
with rigidity. The detailed variation with rigidity of the flux spectral index
is presented. The spectral index is progressively hardening at high rigidities.
Solar effects are also discussed.

16
The categories of this paper are: stat
25
The categories of this paper are: patt-sol
23
The categories of this paper are: solv-int
4
The categories of this paper are: cond-mat
11
The categories of this paper are: hep-lat
15
The categories of this paper are: nucl-ex
9
The categories of this paper are: nlin
22
The categories of this paper are: chao-dyn
1
The categories of this paper are: cs
27
The categories of this paper are: comp-gas
24
The categories of this paper are: dg-ga
35
The categories of this paper are: mtrl-th
20
The categories of this paper are: acc-phys
3
The categories of this paper are: physics
7
The categories of this paper are: hep-th
30
The categories of this paper are: q-alg