AI 中文总结
利用MIMAC探测器在莫达讷地下实验室搜索定向暗物质，通过运行特定低压气体混合物重建核反冲三维轨迹，经数据分析比较信号与非源区域事件率，未在天鹅座方向发现事件过剩，设定了自旋相关的WIMP-质子截面上限。
AI 中文摘要
我们展示了一项在莫达讷地下实验室使用MIMAC（微室阵列）探测器进行的定向暗物质搜索。探测器在30毫巴下运行i-C4H10和50% CHF3的低压气体混合物，无任何屏蔽，可重建6升有效体积内产生的核反冲的三维轨迹。方向性是区分真正的WIMP信号与产生相同反冲的背景（如中子）的关键工具。我们分析了来自两个独立腔室的数据，有效曝光时间分别为495.1天和354.2天。通过将重建轨迹投影到星系地图上并根据WIMP质量应用移动运动学能量切割，我们将信号方向的事件率与多个非源区域进行比较。在天鹅座方向未发现明显的事件过剩，我们设定了自旋相关的WIMP-质子截面的上限。
英文摘要
We present a directional dark matter search using the MIMAC (Micro-tpc Matrix of Chambers) detector at the Modane Underground Laboratory. Operating a low-pressure gas mixture of i-C4H10 and 50% CHF3 at 30 mbar, without any shielding, the detector allows the reconstruction of the 3D tracks of nuclear recoils produced in the 6-liter active volume. Directionality is a crucial tool to discriminate true WIMP signals from those of background producing identical recoils, such as neutrons. We analyze data from two independent chambers with effective exposures of 495.1 and 354.2 days, respectively. To estimate the background directly from the data, we apply a standard ON/OFF spatial analysis. By projecting the reconstructed tracks onto the galactic map and applying a moving kinematic energy cut depending on the WIMP mass, we compare the event rate in the signal direction with multiple OFF-source regions. Finding no significant excess of events in the direction of the Cygnus constellation, we set an upper limit on the spin-dependent WIMP-protoncross section.
