[Zhang, Yuan-Yuan;Qin, Guang-You;Wang, Xin-Nian] Cent China Normal Univ, Key Lab Quark & Lepton Phys MOE, Wuhan 430079, Hubei, Peoples R China.^[Zhang, Yuan-Yuan;Qin, Guang-You;Wang, Xin-Nian] Cent China Normal Univ, Inst Particle Phys, Wuhan 430079, Hubei, Peoples R China.^[Wang, Xin-Nian] Lawrence Berkeley Natl Lab, Nucl Sci Div, Berkeley, CA 94720 USA.