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Radiative energy losses are very important in regulating the cosmic ray electron and/or positron (CRE) spectrum during their propagation in the Milky Way. Particularly, the Klein–Nishina (KN) effect of the inverse Compton scattering (ICS) results in less efficient energy losses of high-energy electrons, which is expected to leave imprints on the propagated electron spectrum. It has been proposed that the hardening of CRE spectra around 50 GeV observed by Fermi-LAT, AMS-02, and DAMPE could be due to the KN effect. We show in this work that the transition from the Thomson regime to the KN regime of the ICS is actually quite smooth compared with the approximate treatment adopted in some previous works. As a result, the observed spectral hardening of CREs cannot be explained by the KN effect. It means that an additional hardening of the primary electrons spectrum is needed. We also provide a parameterized form for the accurate calculation of the ICS energy-loss rate in a wide energy range. [ABSTRACT FROM AUTHOR]

Low energy cosmic rays are modulated by the solar activity when they propagation in the heliosphere, leading to ambiguities in understanding their acceleration at sources and propagation in the Milky Way. By means of the precise measurements of the e − , e + , e − + e + , and e + / (e − + e +) spectra by AMS-02 near the Earth, as well as the very low energy measurements of the e − + e + fluxes by Voyager-1 far away from the Sun, we derive the local interstellar spectra (LIS) of e − and e + components individually. Our method is based on a non-parametric description of the LIS of e − and e + and a force-field solar modulation model. We then obtain the evolution of the solar modulation parameters based on the derived LIS and the monthly fluxes of cosmic ray e − and e + measured by AMS-02. To better fit the monthly data, additional renormalization factors for e − and e + have been multiplied to the modulated fluxes. We find that the inferred solar modulation parameters of positrons are in good agreement with that of cosmic ray nuclei, and the time evolutions of the solar modulation parameters of electrons and positrons differ after the reversal of the heliosphere magnetic field polarity, which shows clearly the charge-sign dependent modulation effect. [ABSTRACT FROM AUTHOR]

We propose a flavored U ( 1 ) e μ neutrino mass and dark matter (DM) model to explain the recent DArk Matter Particle Explorer (DAMPE) data, which feature an excess on the cosmic ray electron plus positron flux around 1.4 TeV. Only the first two lepton generations of the Standard Model are charged under the new U ( 1 ) e μ gauge symmetry. A vector-like fermion ψ , which is our DM candidate, annihilates into e ± and μ ± via the new gauge boson Z ′ exchange and accounts for the DAMPE excess. We have found that the data favors a ψ mass around 1.5 TeV and a Z ′ mass around 2.6 TeV, which can potentially be probed by the next generation lepton colliders and DM direct detection experiments. [ABSTRACT FROM AUTHOR]