标题： 通过完全轻子衰变的超重粒子暗物质候选者探测异常正电子比例的起源 显示英文标题

标题： Probing the anomalous positron fraction origin with fully leptonic decaying gravitino dark matter candidates

摘要： 通过空间实验PAMELA、AMS-02、CALET、DAMPE和Fermi-LAT测量的电子和正电子宇宙射线通量在高能量下表现出与标准天体物理源预期不符的异常行为。 特别是，AMS-02的观测提供了正电子和电子新来源的有力证据，但其起源仍然未知。 可能的场景包括暗物质的贡献或未解析的天体物理源，例如附近的脉冲星。 已经表明，主要基于暗物质的解释倾向于过度产生伽马射线，从而与河外伽马射线背景（EGB）的测量发生冲突。 尽管这种情况似乎相当普遍，但最终取决于暗物质候选者的性质。 在这项工作中，我们重新审视了一个模型，其中引力子是通过R宇称破坏耦合衰变为标准模型粒子的暗物质候选者。 我们表明，由三线耦合允许的衰变通道相比由双线耦合允许的通道会产生更多的电子和正电子以及更少的光子。 事实上，仅考虑AMS-02数据时，我们发现三线模型与EGB约束相容。 然而，当考虑DAMPE或CALET对电子和正电子通量之和的测量结果而不是AMS-02数据时，这一结果可能会改变。 因此，为了进一步评估这个模型，需要澄清这些实验收集的数据之间的差异。 显示英文摘要

摘要： The flux of electron and positron cosmic rays measured by the space-based experiments PAMELA, AMS-02, CALET, DAMPE and Fermi-LAT shows an unexpected behaviour at high energies, in comparison with expectations from standard astrophysical sources. In particular, AMS-02 observations provide compelling evidence for a new source of positrons and electrons whose origin is still unknown. Plausible scenarios include either the contribution of dark matter or unresolved astrophysical sources, such as nearby pulsars. It has been shown that explanations based mostly on dark matter, tend to overproduce gamma-rays, entering in conflict with measurements of the extra-galactic gamma-ray background (EGB). Although this situation seems to be quite generic, it ultimately depends on the properties of the dark matter candidate. In this work we revisit a model in which the gravitino is a dark matter candidate decaying to SM particles through R-parity violating couplings. We show that decay channels allowed by trilinear couplings produce more electrons and positrons and fewer photons in comparison to channels allowed by bilinear couplings. Indeed, when considering AMS-02 data alone we find that the trilinear model is compatible with EGB constraints. However, this result may change when DAMPE or CALET measurements of the sum of electrons and positrons fluxes are considered instead of AMS-02 data. Therefore, in order to evaluate this model further, discrepancies between the data collected by these experiments need to be clarified