Search for Lepton Number and Lepton Flavour Violation proces ses at the NA62 experiment at CERN

这项研究集中在欧洲核子研究中心NA62实验的两个方面。第一个目标是开发未来安装在NA62高强度强子束上的差动切伦科夫探测器的光学系统设计。未来的探测器与目前的探测器不同之处在于，它使用的是氢气辐射体气体，而不是氮气，这使得探测器薄了约三倍，并减少了束流粒子的多次散射，从而减少了相关的背景。第二个目标是利用NA62实验在2016-2018年使用缩小的控制触发器收集的大型数据集，在衰变K+--&pi+p0A‘中搜索无质量暗光子(A’)的产生，这是NA62隐藏扇区搜索方案的一部分。

The research is focused on two aspects of the NA62 experiment at CERN. The first goal is the development of the design of the optical system for a future differential Cherenkov detector to be installed in the NA62 high-intensity hadron beam. The future detector is different from the current one in that it uses hydrogen radiator gas rather than nitrogen, which makes the detector thinner by a factor of about three and reduces multiple scattering of beam particles and therefore the associated background. The second goal is the search for the production of the massless dark photon (A') in the decay K+ --> pi+ pi0 A' using the large data set collected by the NA62 experiment using a downscaled control trigger in 2016-2018, which is a part of the NA62 hidden sector search programme.