[1] China Univ Min & Technol, Beijing 100083, Peoples R China
[2] Chinese Acad Sci, Inst High Energy Phys, Beijing 100049, Peoples R China
[3] Natl Univ Sci & Technol NUST, Sch Nat Sci SNS, Dept Phys, Sect H-12, Islamabad 44000, Pakistan
[4] Univ Chinese Acad Sci, Sch Phys, Beijing 100049, Peoples R China