论文标题
在Belle II搜索暗物质的新渠道
New channel to search for dark matter at Belle II
论文作者
论文摘要
我们在Belle II提出了一个新的``消失的正电子轨道''通道，以搜索暗物质，其中在主要相互作用顶点在电磁量热仪中产生的正电子量与电磁热量计散射以产生暗物质颗粒。这种散射可以通过用原子电子歼灭，或带有靶核的Bremsstrahlung过程。主要背景是由于光子和中子在相同散射中产生的，然后逃脱检测。我们需要大量的能量缺失，并在KLM检测器中否决某些活动，以抑制此类背景。为了说明新通道的敏感性，我们考虑了一种新的物理模型，其中暗物质通过暗光子与标准模型相互作用，黑物质主要衰减到暗物质。我们发现我们提出的通道可以探测一些目前未开发的参数空间，从而超过了Belle II和Na64约束的单声道通道。
We propose a new ``disappearing positron track'' channel at Belle II to search for dark matter, in which a positron that is produced at the primary interaction vertex scatters with the electromagnetic calorimeter to produce dark matter particles. Such scatterings can occur via either annihilation with atomic electrons, or the bremsstrahlung process with target nuclei. The main backgrounds are due to photons and neutrons that are produced in the same scatterings and then escape detection. We require a large missing energy and further veto certain activities in the KLM detector to suppress such backgrounds. To illustrate the sensitivity of the new channel, we consider a new physics model where dark matter interacts with the standard model via a dark photon, which decays predominantly to dark matter; we find that our proposed channel can probe some currently unexplored parameter space, surpassing both the mono-photon channel at Belle II and the NA64 constraints.
