[1] Peking Univ, Sch Phys, Beijing 100871, Peoples R China
[2] Peking Univ, State Key Lab Nucl Phys & Technol, Beijing 100871, Peoples R China
[3] Peking Univ, Ctr High Energy Phys, Beijing 100871, Peoples R China
[4] Peking Univ, Ctr Hist & Philosophy Sci, Beijing 100871, Peoples R China