希格斯玻色子通过对称性自发破缺自恰地赋予其他基本粒子以质量，被很多人称为上帝粒子，其重要性可见一斑。2012年在欧洲核子中心大型强子对撞机上希格斯玻色子的发现表明标准模型在描述弱相互作用方面取得了很大的成功，标准模型框架内所有的基本粒子已经被证实。然而当前对超越标准模型的新物理的探索更是方兴未艾。超出标准模型的最小超对称模型预言了五种不同的希格斯粒子，其中包括CP-odd(C宇称和P宇称乘积为奇)的希格斯粒子A0，它的质量低于bb-bar的产生阈值，窄的Upsilon粒子的辐射衰变是寻找A0最佳的反应过程。本项目依托Belle实验获取的世界上最大的Upsilon(1S,2S)的数据样本，在Upsilon(1S,2S)的辐射衰变过程中对A0进行寻找，A0衰变到tau子对和缪子对。我们的测量将对最小超对称模型进行精确检验和约束，为新物理的寻找和研究提供丰富的实验信息。

The mass of the elementary particles is given by the spontaneous symmetry breaking of the Higgs boson, which is called the “God Particle” due to the significant importance. The discovery of the Higgs boson at the Large Hadron Colliders in CERN in 2012 shows that the standard model has achieved great success in describing the weak interaction. All elementary particles in the standard model have been confirmed until now. However, exploring the new physics beyond the standard model is now in the ascendant. The minimal supersymmetric standard model predicted five different Higgs bosons, including a CP-odd Higgs A0 with a mass lower than the bb-bar threshold. The best channel to search for such A0 state is the radiative decays of the narrow Upsilon states. This project relies on the largest data sample of Upsilon(1S,2S) collected at Belle to search for the A0 state in their radiative decays in the final states of tau tau and mu mu. Our measurements will accurately test and constrain the minimal supersymmetric standard model, and provide abundant experimental information for the search and study of new physics.