1. Particle Physics Research Centre, School of Physics and Astronomy, Queen Mary University of London, London E1 4NS, United Kingdom
2. College of Physics, Sichuan University, 610064 Chengdu, People’s Republic of China
3. Centre for Condensed Matter and Materials Physics, School of Physics and Astronomy, Queen Mary University of London, London E1 4NS, United Kingdom
4. School of Biological and Chemical Sciences, Queen Mary University of London, London E1 4NS, United Kingdom