We study a scenario that a hidden gaugino dark matter decays into the standard-model particles (and their supersymmetric partners) through a kinetic mixing with the gaugino of a U(1)B-L broken at a scale close to the grand unification scale. We show that decay of the hidden gaugino can explain excesses in the cosmic-ray electrons and positrons observed by PAMELA and Fermi.
We perform a detailed study of scalar dark matter with triplet Higgs extensions of the Standard Model in order to explain the cosmic ray electron and positron excesses reported by AMS-02 and DAMPE. A detailed analysis of AMS-02 positron excess reveals that for different orderings (normal, inverted and quasi-degenerate) of neutrino mass, the hybrid triplet Higgs portal framework is more favored with respect to the single triplet Higgs portal for TeV scale dark matter. We also show that the resonant peak and continuous excess in DAMPE cosmic ray data can be well explained with the hybrid triplet…
The precise measurements of energy spectra of cosmic ray positrons and/or electrons by recent experiments show clear excesses above 10 GeV. Moreover, a potential sharp spectral feature was suggested by the Dark Matter Particle Explorer (DAMPE) data. These results inspire quite a number of discussions on the connection with either the annihilation/decay of dark matter (DM) or the astrophysical origins. Here we discuss a DM scenario in which DM particles could annihilate and decay into standard model particle pairs simultaneously. In this model, the peak structure is due to the DM annihilation i…
We explain the excess of the antiproton fraction recently reported by the AMS-02 experiment by considering collisions between cosmic-ray protons accelerated by a local supernova remnant (SNR) and the surrounding dense cloud. The same "$pp$-collisions" provide the right ratio of daughter particles to fit the observed positron excess simultaneously in the natural model parameters. The supernova happened in relatively lower metalicity than the major cosmic-ray sources. The cutoff energy of electrons marks the supernova age of $\sim 10^{5}$ years, while the antiproton excess may extend to higher e…
We propose a novel mechanism to explain the positron excesses, which are observed by satellite-based telescopes including PAMELA and AMS-02, in dark matter (DM) scenarios. The novelty behind the proposal is that it makes direct use of DM around the Galactic Center where DM populates most densely, allowing us to avoid tensions from cosmological and astrophysical measurements. The key ingredients of this mechanism include DM annihilation into unstable states with a very long laboratory-frame life time and their "retarded" decay near the Earth to electron-positron pair(s) possibly with other (in)…
The Dark Matter Particle Explorer (DAMPE) satellite detector announced its first result for measuring the cosmic-ray electron/positron (CRE) energy spectrum up to 4.6TeV, including a tentative peak-like event excess at (1.3-1.5)TeV. In this work, we uncover a significant hidden excess in the DAMPE CRE spectrum over the energy range (0.6-1.1)TeV, which has a non-peak-like structure. We propose a new mechanism to explain this excess by a set of 1.5TeV $μ^\pm$ events with subsequent decays into $e^\pm$ plus neutrinos. For explaining this new excess together with the peak excess around 1.4TeV, we …
Intriguing signals with excesses over expected backgrounds have been observed in many astrophysical and terrestrial settings, which could potentially have a dark matter origin. Astrophysical excesses include the Galactic Center GeV gamma-ray excess detected by the Fermi Gamma-Ray Space Telescope, the AMS antiproton and positron excesses, and the 511 and 3.5 keV X-ray lines. Direct detection excesses include the DAMA/LIBRA annual modulation signal, the XENON1T excess, and low-threshold excesses in solid state detectors. We discuss avenues to resolve these excesses, with actions the field can ta…
Growing evidence reveals universal hardening on various cosmic ray spectra, e.g. proton, positron, as well as antiproton fraction. Such universality may indicate they have a common origin. In this paper, we argue that these widespread excesses can be accounted for by a nearby supernova remnant surrounded by a giant molecular cloud. Secondary cosmic rays ($\rm p$, $\rm e^+$) are produced through the collisions between the primary cosmic ray nuclei from this supernova remnant and the molecular gas. Different from the background, which is produced by the ensemble of large amount of sources in the…
Spin identification of the mono-Z$^{\prime}$ resonance in muon-pair production at the ILC with simulated electron-positron collisions at $\sqrt{s}$ = 500 GeV
Centre for Theoretical Physics, The British University in Egypt（埃及英国大学理论物理中心）
In the light of the latest measurements on the total $e^+ + e^-$ flux by CALET and DAMPE experiments, we revisit the multicomponent leptonically decaying dark matter (DM) explanations to the cosmic-ray electron/positron excesses observed previously. Especially, we use the single and double-component DM models to explore the compatibility of the AMS-02 positron fraction with the new CALET or DAMPE data. It turns out that neither single nor double-component DM models are able to fit the AMS-02 positron fraction and DAMPE total $e^+ + e^-$ flux data simultaneously. On the other hand, for the comb…
