Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Deriving the cosmic ray spectrum from gamma-ray observations   A fundamental problem of cosmic ray (CR) physics is the determination of the
average properties of Galactic CRs outside the Solar system. Starting from
COS-B data in the 1980's, gamma-ray observations of molecular clouds in the
Gould Belt above the Galactic plane have been used to deduce the Galactic CR
energy spectrum. We reconsider this problem in view of the improved precision
of observational data which in turn require a more precise treatment of photon
production in proton-proton scatterings. We show that the spectral shape
$dN/dp\propto p^{-2.85}$ of CR protons as determined by the PAMELA
collaboration in the energy range 80 GeV<pc<230 GeV is consistent with the
photon spectra from molecular clouds observed with Fermi-LAT down to photon
energies E\sim 1-2 GeV. Adding a break of the CR flux at 3 GeV, caused by a
corresponding change of the diffusion coefficient, improves further the
agreement in the energy range 0.2-3 GeV.

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The categories of this paper are: hep-ex
32
The categories of this paper are: atom-ph
14
The categories of this paper are: math-ph
9
The categories of this paper are: nlin
37
The categories of this paper are: supr-con
11
The categories of this paper are: hep-lat
1
The categories of this paper are: cs
7
The categories of this paper are: hep-th
31
The categories of this paper are: ao-sci
27
The categories of this paper are: comp-gas
5
The categories of this paper are: gr-qc
33
The categories of this paper are: plasm-ph
36
The categories of this paper are: cmp-lg
10
The categories of this paper are: q-bio
22
The categories of this paper are: chao-dyn
24
The categories of this paper are: dg-ga