Atribución 3.0 España. © ©2012 CERN  for the benefit of the CMS Collaboration. Published by Elsevier B.V. Open access under CC BY-NC-ND licenseExcepto si se señala otra cosa, la licencia del ítem se describe como Atribución 3.0 España. © ©2012 CERN for the benefit of the CMS Collaboration. Published by Elsevier B.V. Open access under CC BY-NC-ND license