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arXiv · 1211.6905

Low energy cosmic ray positron fraction explained by charge-sign dependent solar modulation

Luca Maccione
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Abstract

We compute cosmic ray (CR) nuclei, proton, antiproton, electron and positron spectra below 1 TeV at Earth by means of a detailed transport description in the galaxy and in the solar system. CR spectra below 10 GeV are strongly modified by charge-sign dependent propagation effects. These depend on the polarity of the solar magnetic field and therefore vary with the solar cycle. The puzzling discrepancy between the low-energy positron fraction measured by PAMELA and AMS-01 is then easily explained by their different data-taking epochs. We reproduce the observed spectra of CR light nuclei within the same galactic and solar-system propagation model.

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Luca Maccione. 2012-11-29. Low energy cosmic ray positron fraction explained by charge-sign dependent solar modulation. https://doi.org/10.1103/physrevlett.110.081101

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