作者机构:[1]College of Physics, University of Chinese Academy ofSciences, Yuquanlu 19A, Beijing 100049, China, [2]Theoretical Physics Center for Science Facilities, Institute ofHigh Energy Physics, Beijing 100049, China
相关基金:This work was supported by the CAS President's International Fellowship Initiative (No. 2015PM008), and the National Natural Science Foundation of China (Nos. 11135011 and 11575190).Acknowledgments M. Ruggieri would like to acknowledge fruitful discussions with M. Chernodub and M. Frasca.