Implications of current nuclear cross sections on secondary cosmic rays with the upcoming DRAGON2 code. (arXiv:2101.01547v3 [astro-ph.HE] UPDATED)
<a href="http://arxiv.org/find/astro-ph/1/au:+Luque_P/0/1/0/all/0/1">Pedro de la Torre Luque</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Mazziotta_M/0/1/0/all/0/1">Mario Nicola Mazziotta</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Loparco_F/0/1/0/all/0/1">Francesco Loparco</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Gargano_F/0/1/0/all/0/1">Fabio Gargano</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Serini_D/0/1/0/all/0/1">Davide Serini</a>
Current measurements of cosmic-ray fluxes have reached unprecedented accuracy
thanks to the new generation of experiments, and in particular the AMS-02
mission. At the same time, significant progress has been made in the
propagation models of galactic cosmic rays. These models include several
propagation parameters, which are usually inferred from the ratios of secondary
to primary cosmic rays, and which depend on the cross sections describing the
collisions among the various species of cosmic-ray nuclei. At present, our
knowledge of these cross sections in the energy range where cosmic-ray
interactions occur is limited, and this is a source of uncertainties in the
predicted fluxes of secondary cosmic-ray nuclei. In this work we study the
impact of the cross section uncertainties on the fluxes of light secondary
nuclei (Li, Be, B) using a preliminary version of the upcoming {tt DRAGON2}
code. We first present a detailed comparison of the secondary fluxes computed
by implementing different parametrizations for the network of spallation cross
sections. Then, we propose for the first time the use of
secondary-over-secondary cosmic-ray flux ratios as a tool to investigate the
consistency of cross sections models and give insight of the overall
uncertainties coming from the cross sections parametrizations. We show that the
uncertainties inferred from the cross section data are enough to explain the
discrepancies in the Be and Li fluxes with respect to the AMS-02 data, with no
need of a primary component in their spectra. In addition, we show that the
fluxes of B, Be and Li can be simultaneously reproduced by rescaling their
cross sections within the experimental uncertainty. Finally, we also revisit
the diffusive estimation of the halo size, obtaining good agreement with
previous works and a best fit value of $6.8 pm 1$ kpc from the most updated
cross sections parametrizations.
Current measurements of cosmic-ray fluxes have reached unprecedented accuracy
thanks to the new generation of experiments, and in particular the AMS-02
mission. At the same time, significant progress has been made in the
propagation models of galactic cosmic rays. These models include several
propagation parameters, which are usually inferred from the ratios of secondary
to primary cosmic rays, and which depend on the cross sections describing the
collisions among the various species of cosmic-ray nuclei. At present, our
knowledge of these cross sections in the energy range where cosmic-ray
interactions occur is limited, and this is a source of uncertainties in the
predicted fluxes of secondary cosmic-ray nuclei. In this work we study the
impact of the cross section uncertainties on the fluxes of light secondary
nuclei (Li, Be, B) using a preliminary version of the upcoming {tt DRAGON2}
code. We first present a detailed comparison of the secondary fluxes computed
by implementing different parametrizations for the network of spallation cross
sections. Then, we propose for the first time the use of
secondary-over-secondary cosmic-ray flux ratios as a tool to investigate the
consistency of cross sections models and give insight of the overall
uncertainties coming from the cross sections parametrizations. We show that the
uncertainties inferred from the cross section data are enough to explain the
discrepancies in the Be and Li fluxes with respect to the AMS-02 data, with no
need of a primary component in their spectra. In addition, we show that the
fluxes of B, Be and Li can be simultaneously reproduced by rescaling their
cross sections within the experimental uncertainty. Finally, we also revisit
the diffusive estimation of the halo size, obtaining good agreement with
previous works and a best fit value of $6.8 pm 1$ kpc from the most updated
cross sections parametrizations.
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