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A worker walks in the CERN’s Large Hadron Collider (LHC) tunnel during maintenance works on July 19, 2013 in Meyrin, near Geneva. Tests at the world’s biggest collider have provided the most exhaustive confirmation to date of the Standard Model, a four-decade-old conceptual framework for fundamental particles, CERN said. AFP PHOTO / FABRICE COFFRINI (Photo credit should read FABRICE COFFRINI/AFP/Getty Images)