Search

Abstract: The recently reported positron fraction up to ∼350 GeV by AMS-02 seems to have tension with the total electron/positron spectra detected by Fermi and HESS, for either pulsar or dark matter annihilation/decay scenario as the primary positron sources. In this work we will show that the tension will be removed by an adjustment of the primary electron spectrum. If the primary electron spectrum becomes harder above ∼50 GeV, similar as the cosmic ray nuclei spectrum, the AMS-02 positron fraction and Fermi/HESS data can be well fitted by both the pulsar and dark matter models. This result may be suggestive of a common origin of the cosmic ray nuclei and the primary electrons. Furthermore, this study also implies that the properties of the extra sources derived from the fitting to the AMS-02 data should depend on the form of background. [Copyright &y& Elsevier]

Abstract: Recently, a tentative 130 GeV γ-ray line signal was identified by quite a few groups. If correct it would constitute a “smoking gun” for dark matter annihilations. Interestingly, the spectra of the cosmic ray electrons detected by PAMELA and Fermi-LAT both show tiny wiggle-like structure at ∼100 GeV, which might indicate a weak signal of the annihilation of ∼130 GeV dark matter particles into electrons/positrons with a velocity-weighted cross section . The prospect of identifying such a potential weak dark-matter-annihilation electron and/or positron component by AMS-02, a mission to measure the high energy cosmic ray spectra with unprecedented accuracy, is investigated. [Copyright &y& Elsevier]