基于加速器缪子源的新物理研究

中微子振荡实验表明中微子具有非零质量，但是中微子质量起源以及是否存在带电轻子味道破坏过程仍然没有答案。近年来，精确测量中微子性质和寻找带电轻子味破坏过程一直是国际高能物理学界研究热点。与中微子质量相关的新物理模型层出不穷，引入中微子新相互作用，同时预言可观测量级的带电轻子味道破坏过程，特别是缪子偶素转化为反缪子偶素过程，当今最佳实验约束由1999年的PSI实验给出。当前，基于中国散裂中子源建造我国第一条加速器缪子源的项目(EMuS)已提上日程，届时我国将建成强度达到PSI实验100倍的正缪子源且可提供高通量加速器中微子。本项目适时开展基于加速器缪子源的新物理研究，重点关注精确测量中微子振荡及中微子与原子核的相干散射过程，以检验三代中微子混合理论的有效性；探寻是否存在中微子新相互作用；探究缪子偶素转化为反缪子偶素实验潜力，筛选和限制中微子质量新物理模型，评估探测器要求，为重大科学突破提供支持

Neutrino oscillation experiments have established the fact that neutrinos are massive particles. However, it is unknown how neutrino masses are generated and whether there are charged lepton-flavor violating processes (cLFV). Precision measurement of neutrino properties and searching for cLFV are hot topics in high-energy physics around the world. Lots of neutrino mass models with new physics beyond Standard Model have been proposed, introducing non-standard neutrino interactions and providing the observable charged lepton-flavor violating processes, like muonium to antimuonium conversions, on which the best constraint came from the PSI experiment in 1999. There are no other muonium experiments since then. With the stable running of China Spallation Neutron Source and a plan to upgrade it to the higher luminosity, the first Chinese Experimental Muon Source (EMuS) is on the way. EMuS will provide the positive muons with the intensity more than two orders of magnitude larger compared to the one at PSI in 1999. Meanwhile, a large amount of accelerator neutrinos can be created simultaneously there. This proposal will conduct physics performance study at the accelerator muon source, with emphasis on precision measurement of neutrino oscillation and neutrino-nucleus coherent scatterings to check the validity of three-neutrino mixing framework, looking for non-standard neutrino interactions, and searching for muonium to antimuonium conversions to select and constrain the neutrino mass models as well as evaluate the requirements for detection technologies to pave the way for the scientific breakthroughs.