Testing astrophysical models for the PAMELA positron excess with cosmic ray nuclei - Astrophysics > High Energy Astrophysical PhenomenaReport as inadecuate




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Abstract: The excess in the positron fraction reported by the PAMELA collaboration hasbeen interpreted as due to annihilation or decay of dark matter in the Galaxy.More prosaically, it has been ascribed to direct production of positrons bynearby pulsars, or due to pion production during stochastic acceleration ofhadronic cosmic rays in nearby sources. We point out that measurements ofsecondary nuclei produced by cosmic ray spallation can discriminate betweenthese possibilities. New data on the titanium-to-iron ratio from the ATIC-2experiment support the hadronic source model above and enable a prediction tobe made for the boron-to-carbon ratio at energies above 100 GeV. Presently, allcosmic ray data are consistent with the positron excess being astrophysical inorigin.



Author: Philipp Mertsch, Subir Sarkar Oxford

Source: https://arxiv.org/







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