1. Department of Physics, School of Engineering Sciences, KTH Royal Institute of Technology, AlbaNova University Center, Roslagstullsbacken 21, SE-106 91 Stockholm, Sweden
2. The Oskar Klein Centre for Cosmoparticle Physics, AlbaNova University Center, Roslagstullsbacken 21, SE-106 91 Stockholm, Sweden
3. University of Iceland, Science Institute, Dunhaga 3, IS-107 Reykjavik, Iceland
4. Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China
5. School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100049, China