[1] Chinese Acad Sci, Inst Modern Phys, Lanzhou 730000, Peoples R China
[2] Univ Chinese Acad Sci, Sch Nucl Sci & Technol, Beijing 101408, Peoples R China
[3] Nankai Univ, Sch Phys, Tianjin 300071, Peoples R China
[4] Zhengzhou Univ, Sch Phys & Microelect, Zhengzhou 450001, Henan, Peoples R China
[5] Lanzhou Univ, Lanzhou Ctr Theoret Phys, Key Lab Theoret Phys Gansu Prov, Lanzhou 730000, Peoples R China