Implications of the first AMS-02 measurement for dark matter annihilation and decay
Implications of the first AMS-02 measurement for dark matter annihilation and decay
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DOI：
10.1088/1475-7516/2013/11/026
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发表时间：
2013-04
影响因子：
6.4
通讯作者：
Hong-Bo Jin;Yue-Liang Wu;Yu-feng Zhou
中科院分区：
文献类型：
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作者：
Hong-Bo Jin;Yue-Liang Wu;Yu-feng Zhou
根据AMS-02实验首次测量到的正电子分数，我们对Pamela、Fermi-LAT和AMS-02的最新数据在各种传播模型中关于暗物质(DM)湮灭和衰变的解释进行了详细的全局分析。对于轻子末态为2E、2微米、2微微米、4微微米、4微微米和4微微子的通道，得到了Dm粒子质量和湮灭截面或衰变寿命的允许区域。结果表明，在常规天体物理背景下，如果DM粒子主要湮没成2微米(4微米)的终态，仅AMS-02正电子分数数据就有利于Dm粒子质量接近500(800)GeV，这明显低于费米-LAT电子和正电子总通量数据所支持的结果。两个实验所允许的区域在高置信度水平(99.99999%C.L.)下不重叠。我们考虑了一些具有不同晕高Z(H)、扩散参数D-0和增量(1/2)以及初级核子源功率指数Gamma(p1/p2)的传播模型。电子本底的归一化和斜率也允许变化。我们发现，在Z(H)和D-0较大的传播模型中，两个实验之间的张力只能略微减小。对于末态为2tau和4tau的湮没通道，近似于S(-1)的10(-23)cm(-3)，这有利于在10(-23)cm(-3)以上具有较大截面的TeV尺度DM粒子。在所有考虑的轻子通道中，目前的数据支持DM湮灭而不是DM衰变的情景。在衰变情形中，电荷不对称的Dm衰变略受青睐。
In light of the first measurement of the positron fraction by the AMS-02 experiment, we perform a detailed global analysis on the interpretation of the latest data of PAMELA, Fermi-LAT, and AMS-02 in terms of dark matter (DM) annihilation and decay in various propagation models. The allowed regions for the DM particle mass and annihilation cross section or decay life-time are obtained for channels with leptonic final states: 2e, 2 mu, 2 tau, 4e, 4 mu and 4 tau. We show that for the conventional astrophysical background the AMS-02 positron fraction data alone favour a DM particle mass similar to 500 (800) GeV if DM particles annihilate dominantly into 2 mu (4 mu) final states, which is significantly lower than that favoured by the Fermi-LAT data of the total flux of electrons and positrons. The allowed regions by the two experiments do not overlap at a high confidence level (99.99999%C.L.). We consider a number of propagation models with different halo height Z(h), diffusion parameters D-0 and delta(1/2), and power indices of primary nucleon sources gamma(p1/p2). The normalization and the slope of the electron background are also allowed to vary. We find that the tension between the two experiments can be only slightly reduced in the propagation model with large Z(h) and D-0. The consistency of fit is improved for annihilation channels with 2 tau and 4 tau final states which favour TeV scale DM particle with large cross sections above similar to 10(-23) cm(3)s(-1). In all the considered leptonic channels, the current data favour the scenario of DM annihilation over DM decay. In the decay scenario, the charge asymmetric DM decay is slightly favoured.