[1] STFC Rutherford Appleton Lab, Particle Phys Dept, Didcot OX11 0QX, England
[2] Univ Sheffield, Dept Phys & Astron, Western Bank, Sheffield S10 2TN, England
[3] STFC Rutherford Appleton Lab, Innovat Technol Access Ctr, Didcot OX11 0FA, England
[4] Chinese Acad Sci, Inst High Energy Phys, Beijing 100049, Peoples R China
[5] Univ Chinese Acad Sci, Beijing 100049, Peoples R China
[6] Carleton Univ, Dept Phys, Ottawa, ON K1S 5B6, Canada
[7] Carleton Univ, Dept Elect, Ottawa, ON K1S 5B6, Canada
[8] Zhejiang Univ, Sch Phys, Hangzhou 310058, Peoples R China