Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The Cosmic Ray Antiproton Spectrum and a Limit on the Antiproton
  Lifetime   Measurements of the cosmic ray pbar/p ratio are compared to predictions from
an inhomogeneous leaky box model of Galactic secondary pbar production combined
with an updated heliospheric model that modulates the predicted fluxes measured
at the Earth. The heliospheric corrections are crucial for understanding the
low-energy part of the spectrum. The pbar production- propagation-modulation
model agrees with observations. Adding a finite pbar lifetime to the model, we
obtain the limit tau(pbar) > 1.7 Myr (90% C.L.). Restrictions on heliospheric
properties and the cutoff of low-energy interstellar cosmic rays are discussed.

9
The categories of this paper are: nlin
5
The categories of this paper are: gr-qc
14
The categories of this paper are: math-ph
34
The categories of this paper are: chem-ph
8
The categories of this paper are: hep-ex
10
The categories of this paper are: q-bio
13
The categories of this paper are: quant-ph
11
The categories of this paper are: hep-lat
20
The categories of this paper are: acc-phys
15
The categories of this paper are: nucl-ex
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The categories of this paper are: mtrl-th
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The categories of this paper are: eess
2
The categories of this paper are: math
33
The categories of this paper are: plasm-ph
21
The categories of this paper are: adap-org
24
The categories of this paper are: dg-ga