Nonperturbative effect on dark matter annihilation and gamma ray signature from the galactic center
Nonperturbative effect on dark matter annihilation and gamma ray signature from the galactic center
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DOI：
10.1103/physrevd.71.063528
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发表时间：
2005-03-01
影响因子：
5
通讯作者：
Saito, O
中科院分区：
文献类型：
--
作者：
Hisano, J;Matsumoto, S;Saito, O
探测银河系中心暗物质湮灭产生的伽马射线是寻找暗物质的可行技术之一。我们在暗物质具有电弱SU（2）（L）电荷的情况下计算了γ射线通量。这样的暗物质在最小超对称标准模型（MSSM）中实现，当最轻的超对称粒子是类希格斯诺或维诺中性伴子时。当暗物质比弱规范玻色子重时，由于阈值奇异性，微扰中湮灭截面的首阶计算失败。利用非相对论有效理论，我们考虑了暗物质及其SU（2）（L）伙伴的两体态的非微扰效应，并计算了与γ射线通量相关的精确截面。我们发现，湮灭截面可能会增强几个数量级，由于共振时，暗物质的质量大于1 TeV。此外，在MSSM的湮没截面可能会改变的因素，即使当质量约为500 GeV。我们还讨论了GLAST卫星探测器和大型空气切伦科夫望远镜阵列的银河系中心的伽马射线信号的灵敏度。
Detection of gamma rays from dark matter annihilation in the galactic center is one of the feasible techniques to search for dark matter. We evaluate the gamma-ray flux in the case that the dark matter has an electroweak SU(2)(L) charge. Such dark matter is realized in the minimal supersymmetric standard model (MSSM) when the lightest SUSY particle is the Higgsino- or Wino-like neutralino. When the dark matter is heavy compared to the weak gauge bosons, the leading-order calculation of the annihilation cross sections in perturbation breaks down due to a threshold singularity. We take into account nonperturbative effects by using the nonrelativistic effective theory for the two-body states of the dark matter and its SU(2)(L) partner(s), and evaluate precise cross sections relevant to the gamma-ray fluxes. We find that the annihilation cross sections may be enhanced by several orders of magnitude due to resonances when the dark matter mass is larger than 1 TeV. Furthermore, the annihilation cross sections in the MSSM may be changed by factors even when the mass is about 500 GeV. We also discuss sensitivities to gamma-ray signals from the galactic center in the GLAST satellite detector and the large Air Cerenkov Telescope arrays.