The discovery of the Higgs boson is one of the most significant advances of particle physics in recent years. It led to the award of the Nobel Prize in Physics 2013 to Englert and Higgs for the theory explaining the origin of the particle mass. The Nobel Prize cannot conceal the fact that the results about the new particle have been achieved by the experimental physicists of the ATLAS and CMS collaborations, who are among the largest international collaboration of scientists in the world (2898 and 2932 physicists, respectively). This article is dedicated to the study of the organization and operation of the ATLAS and CMS international collaborations. The disparities between countries, structure of collaborative networks, physicists’ cooperative vs. competitive preferences, and emerging properties of research work in large scientific collaborations are reviewed.