Search for 100 MeV to 10 GeV γ-ray lines in the Fermi-LAT data and implications for gravitino dark matter in the μνSSM
Search for 100 MeV to 10 GeV γ-ray lines in the Fermi-LAT data and implications for gravitino dark matter in the μνSSM
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DOI：
10.1088/1475-7516/2014/10/023
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发表时间：
2014-06
影响因子：
6.4
通讯作者：
A. Albert;G. Gómez-Vargas;M. Grefe;C. Muñoz;C. Weniger;E. Bloom;E. Charles;M. Mazziotta;A. Morselli
中科院分区：
文献类型：
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作者：
A. Albert;G. Gómez-Vargas;M. Grefe;C. Muñoz;C. Weniger;E. Bloom;E. Charles;M. Mazziotta;A. Morselli
暗物质的衰变或湮灭可能在γ射线能量范围内产生单色信号。在这项工作中，我们论证了在引力子暗物质衰变的框架下研究这些信号有很强的理论动机，并利用费米-LAT数据搜索了从100 MeV到10GeV的γ谱线。与以前在较高能量下的线搜索不同，本次搜索的灵敏度由所考虑的大部分能量范围内的系统不确定性所主导。我们通过分析来自多个控制区的通量来估计系统效应的大小，并在我们的拟合过程中一致地包括系统的不确定性。我们没有观察到任何重要的信号，并给出了衰变和湮灭暗物质的γ射线发射的模型无关的限制。我们将以前的限制应用于引力子的情况，引力子是超对称场景中著名的暗物质候选者。特别地，R宇称违背‘’μfromν‘’超对称标准模型μνSSM)是一个吸引人的场景，其中包含右手中微子解决了最小超对称标准模型的μ问题，同时解释了中微子质量的起源。同时，R宇称的破坏使得引力微子不稳定，容易衰变成光子和中微子。由于线发射的限制，质量大于约5GeV或寿命小于约1028GeV的μνSSM引力星在95%的置信度下被排除为暗物质候选者。
Dark matter decay or annihilation may produce monochromatic signals in the γ-ray energy range. In this work we argue that there are strong theoretical motivations for studying these signals in the framework of gravitino dark matter decay and we perform a search for γ-ray spectral lines from 100 MeV to 10 GeV with Fermi-LAT data. In contrast to previous line searches at higher energies, the sensitivity of the present search is dominated by systematic uncertainties across most of the energy range considered. We estimate the size of systematic effects by analysing the flux from a number of control regions, and include the systematic uncertainties consistently in our fitting procedure. We have not observed any significant signals and present model-independent limits on γ-ray line emission from decaying and annihilating dark matter. We apply the former limits to the case of the gravitino, a well-known dark matter candidate in supersymmetric scenarios. In particular, the R-parity violating ''μ from ν'' Supersymmetric Standard Model μνSSM) is an attractive scenario in which including right-handed neutrinos solves the μ problem of the Minimal Supersymmetric Standard Model while simultaneously explaining the origin of neutrino masses. At the same time, the violation of R-parity renders the gravitino unstable and subject to decay into a photon and a neutrino. As a consequence of the limits on line emission, μνSSM gravitinos with masses larger than about 5 GeV, or lifetimes smaller than about 1028 s, are excluded at 95% confidence level as dark matter candidates.