Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Nonsecondary origin of cosmic ray positrons   We investigate the possibility of secondary production as the source of
cosmic ray (CR) positrons, taking into account observed electron and antiproton
spectra and allowing that the reported steepening in the AMS-02 positron
spectrum may be due to radiative losses. Using a simple argument based on the
antiproton spectrum, we show that positrons cannot be purely secondary. Namely,
the antiproton to positron ratio requires that positrons be uncooled up to a
few hundred GeV. This requirement implies that CR protons escape from the
Galaxy too quickly to reproduce the observed antiproton flux. We further show
that this result rules out also more complex secondary production scenarios
such as reacceleration and the Nested Leaky Box. Thus, we conclude that while
antiprotons can be produced exclusively in secondary interactions, a primary
source of CR positrons -- be it dark matter or pulsars -- is required to
explain their spectrum.

30
The categories of this paper are: q-alg
18
The categories of this paper are: econ
12
The categories of this paper are: nucl-th
8
The categories of this paper are: hep-ex
34
The categories of this paper are: chem-ph
35
The categories of this paper are: mtrl-th
17
The categories of this paper are: q-fin
7
The categories of this paper are: hep-th
26
The categories of this paper are: bayes-an
16
The categories of this paper are: stat
31
The categories of this paper are: ao-sci
9
The categories of this paper are: nlin
32
The categories of this paper are: atom-ph
22
The categories of this paper are: chao-dyn
29
The categories of this paper are: funct-an
27
The categories of this paper are: comp-gas