Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Study of the 27-day variations in GCR fluxes during 2007-2008 based on
  PAMELA and ARINA observations   Using measurements from the PAMELA and ARINA spectrometers onboard the RESURS
DK-1 satellite, we have examined the 27-day intensity variations in galactic
cosmic ray (GCR) proton fluxes in 2007-2008. The PAMELA and ARINA data allow
for the first time a study of time profiles and the rigidity dependence of the
27-day variations observed directly in space in a wide rigidity range from ~300
MV to several GV. We find that the rigidity dependence of the amplitude of the
27-day GCR variations cannot be described by the same power-law at both low and
high energies. A flat interval occurs at rigidity R = <0.6-1.0> GV with a
power-law index gamma = - 0.13+/-0.44 for PAMELA, whereas for R >= 1 GV the
power-law dependence is evident with index gamma = - 0.51+/-0.11. We describe
the rigidity dependence of the 27-day GCR variations for PAMELA and ARINA data
in the framework of the modulation potential concept using the force-field
approximation for GCR transport. For a physical interpretation, we have
considered the relationship between the 27-day GCR variations and solar wind
plasma and other heliospheric parameters. Moreover, we have discussed possible
implications of MHD modeling of the solar wind plasma together with a
stochastic GCR transport model concerning the effects of corotating interaction
regions.

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The categories of this paper are: chem-ph
9
The categories of this paper are: nlin
25
The categories of this paper are: patt-sol
28
The categories of this paper are: alg-geom
20
The categories of this paper are: acc-phys
0
The categories of this paper are: hep-ph
35
The categories of this paper are: mtrl-th
1
The categories of this paper are: cs
16
The categories of this paper are: stat
19
The categories of this paper are: eess
22
The categories of this paper are: chao-dyn
14
The categories of this paper are: math-ph
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The categories of this paper are: supr-con
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The categories of this paper are: ao-sci
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The categories of this paper are: q-alg
7
The categories of this paper are: hep-th