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arXiv 1412.1663hep-ph
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用二分量暗物质模型解释银河系中心低能$γ$射线过剩

Explaining Low Energy $γ$-ray Excess from the Galactic Centre using a Two Component Dark Matter Model

Anirban Biswas

摘要:

在过去的几年里,费米-LAT卫星望远镜从银河系中心周围的区域观测到了能量范围为$\sim 1$ - $3$ GeV的$γ$射线过剩的迹象。这种多余的$γ$ -射线光谱的性质被发现与银河系中心暗物质湮灭所预期的$γ$ -射线发射是一致的,同时不赞成其他已知的天体物理来源作为这种现象的可能起源。还有报道说,这种多余的$γ$ -射线的光谱和形态可以很好地解释为质量在$30\sim 40$ GeV范围内的暗物质粒子在银河系中心湮灭成${\rm b} \bar{\rm b}$最终状态,湮灭截面为$σ{\rm v}\sim (1.4$ - $2.0)\times 10^{-26}$ cm $^3/$ s。在这项工作中,我们提出了一个两个组件的暗物质模型,两种不同类型的暗物质粒子,即一个复杂的标量和狄拉克费米子被认为是。这两个暗扇区粒子的稳定性保持凭借一个额外的本地U $(1)_{\rm X}$规范对称性。我们发现,我们提出的方案可以提供一个可行的解释,这种异常的过量$γ$ -射线,除了满足所有现有的相关理论以及实验和观测的LHC,普朗克和LUX合作的界限。由此得到的${\rm b} \bar{\rm b}$湮灭通道的较轻暗物质粒子的“有效湮灭截面“的允许范围,最后与Fermi-LAT和DES合作利用各种矮球状星系的数据报道的极限进行了比较。

英文摘要:

Over the past few years, there has been a hint of the $γ$-ray excess observed by the Fermi-LAT satellite borne telescope from the regions surrounding the Galactic Centre at an energy range $\sim 1$-$3$ GeV. The nature of this excess $γ$-ray spectrum is found to be consistent with the $γ$-ray emission expected from dark matter annihilation at the Galactic Centre while disfavouring other known astrophysical sources as the possible origin of this phenomena. It is also reported that the spectrum and morphology of this excess $γ$-rays can well be explained by the dark matter particles having mass in the range $30\sim 40$ GeV annihilating significantly into ${\rm b} \bar{\rm b}$ final state with an annihilation cross section $σ{\rm v}\sim (1.4$ - $2.0)\times 10^{-26}$ cm$^3/$s at the Galactic Centre. In this work, we propose a two component dark matter model where two different types of dark matter particles namely a complex scalar and a Dirac fermion are considered. The stability of both the dark sector particles are maintained by virtue of an additional local U$(1)_{\rm X}$ gauge symmetry. We find that our proposed scenario can provide a viable explanation for this anomalous excess $γ$-rays besides satisfying all the existing relevant theoretical as well as experimental and observational bounds from LHC, PLANCK and LUX collaborations. The allowed range of "effective annihilation cross section" of lighter dark matter particle for the ${\rm b} \bar{\rm b}$ annihilation channel thus obtained, is finally compared with the limits reported by the Fermi-LAT and DES collaborations using data from various dwarf spheroidal galaxies.

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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