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arXiv 1306.2959hep-phastro-ph.CO
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动力学暗物质与AMS光的正电子过剩

Dynamical Dark Matter and the Positron Excess in Light of AMS

Keith R. Dienes, Jason Kumar, Brooks Thomas

摘要:

AMS-02实验最近公布的数据证实,宇宙射线正电子分数随着能量的增加而增加,最高可达约350 GeV。在过去的十年里,试图用暗物质衰变来解释这种正电子过剩的尝试变得越来越复杂,并导致了一些关于衰变中的暗物质粒子的普遍预期:例如,这种粒子不能经历简单的两体衰变到轻子,它们必须具有相当重的TeV尺度质量。在本文中,相比之下,我们表明,动力学暗物质(DDM)不仅可以匹配现有的AMS-02数据的正电子过剩,但也完成了这一壮举显着较轻的暗物质成分经历简单的两体衰变到轻子。此外,我们还证明了这一点可以在不与费米和普朗克对衰变暗物质的许多其他竞争约束相冲突的情况下实现。最后,我们证明了动力学暗物质框架做出了一个相当稳健的预测,即正电子分数应该趋于平稳,然后大致保持恒定,达到约1 TeV,而不会经历任何急剧的下降。事实上,如果我们用衰变的暗物质来解释正电子过剩,我们发现能量小于1 TeV的正电子部分中存在一个平台,可以被视为动力学暗物质的“确凿证据”。

英文摘要:

The AMS-02 experiment has recently released data which confirms a rise in the cosmic-ray positron fraction as a function of energy up to approximately 350 GeV. Over the past decade, attempts to interpret this positron excess in terms of dark-matter decays have become increasingly complex and have led to a number of general expectations about the decaying dark-matter particles: such particles cannot undergo simple two-body decays to leptons, for example, and they must have rather heavy TeV-scale masses. In this paper, by contrast, we show that Dynamical Dark Matter (DDM) can not only match existing AMS-02 data on the positron excess, but also accomplish this feat with significantly lighter dark-matter constituents undergoing simple two-body decays to leptons. Moreover, we demonstrate that this can be done without running afoul of numerous other competing constraints from FERMI and Planck on decaying dark matter. Finally, we demonstrate that the Dynamical Dark Matter framework makes a fairly robust prediction that the positron fraction should level off and then remain roughly constant out to approximately 1 TeV, without experiencing any sharp downturns. Indeed, if we interpret the positron excess in terms of decaying dark matter, we find that the existence of a plateau in the positron fraction at energies less than 1 TeV may be taken as a "smoking gun" of Dynamical Dark Matter.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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