There is convincing observational evidence for an increasing cosmic-ray positron-to-electron ratio at energies larger than ∼10 GeV, at odds with expectations from secondary positron production. The most recent AMS-02 data exhibit an interesting spectral feature consisting of a bump at an energy around 300 GeV followed by a drop around ∼800 GeV. A possible explanation for the most recent data is that the excess positron flux originates from decaying dark matter. Here, we show that models consisting of two dark matter particle species contributing equally to the global cosmological dark matter density provide good fits to the data. The favored models, with a best-fit with χ ²/d.o.f ∼ 2, consist of a first species weighing 750 GeV decaying with a lifetime τ _χ ∼ 10²⁶ s to τ lepton pairs (or to a pair of vector bosons subsequently decaying to a τ pair each), and a second species with a mass around 2.3 TeV decaying to μ lepton pairs. We provide a few possible concrete realizations for this scenario.

有令人信服的观察证据表明，在大于约10 GeV的能量下，宇宙射线正电子与电子之比的增加，与次级正电子生产的预期相悖。最新的AMS-02数据显示出有趣的光谱特征，包括在300 GeV左右的能量突增，然后在约800 GeV左右下降。对于最新数据的可能解释是，过量的正电子通量来自衰变的暗物质。在这里，我们显示了由两个暗物质粒子组成的模型，它们对全球宇宙学暗物质密度的贡献均相等，可以很好地拟合数据。偏爱的车型，拥有最适合用χ ² / d。Ø。F〜2，由第一物种称量750个电子伏特与寿命衰减的τ _χ〜10 ²⁶ s至τ轻子对（或一对矢量玻色子随后衰减到的τ每对），和一第二物种的质量周围2.3 TeV衰减至μ轻子对。我们为这种情况提供了一些可能的具体实现。