[Huang, Huan Zhong] Univ Calif Los Angeles, Dept Phys & Astrophys, Los Angeles, CA 90095 USA.
[Shi, Shusu; Luo, Xiaofeng; Liu, Feng] Cent China Normal Univ, Key Lab Quark & Lepton Phys MOE, Wuhan 430079, Peoples R China.
[Shi, Shusu; Luo, Xiaofeng; Liu, Feng] Cent China Normal Univ, Inst Particle Phys, Wuhan 430079, Peoples R China.
[Wang, Fuqiang] Purdue Univ, Dept Phys, W Lafayette, IN 47907 USA.
[Xu, Nu] Lawrence Berkeley Natl Lab, Nucl Sci Div, Berkeley, CA 94720 USA.