Search for cosmic-ray antideuteron and antihelium with long duration balloon flight data

我们已经用BESS-Polar II数据搜索了宇宙射线反氘核和反氦。我们仔细检查了从南极洲回收的BESS-PolarII有效载荷，并通过新的校准方法获得了探测器在飞行过程中状态的各种关键信息，并提高了探测器的性能。基于这些数据，对反氘核和反氦进行了新的搜索，灵敏度提高了一个数量级。没有观察到候选人。反氦的零观测，加上之前的BESS数据，对我们宇宙附近存在反域提出了最严格的限制。

We have searched for cosmic-ray antideuteron and antihelium with BESS-Polar II data. We carefully examined the recovered BESS-PolarII payload from Antarctica and obtained various key information about the detector status during the flight and improved detector performance with the novel calibration method. Based on the data, new searches were performed for antideuteron and antihelium with improved sensitivity by an order of magnitude. No candidates were observed. Null observation of antihelium, together with previous BESS data, placed the most stringent constraint on existence of anti-domain nearby our universe.