Scientists at the world’s biggest atom smasher hailed the discovery of “the missing cornerstone of physics” Wednesday, cheering the apparent end of a decades-long quest for a new subatomic particle called the Higgs boson, or “God particle,” which could help explain why all matter has mass and crack open a new realm of physics.

First proposed as a theory in the 1960s, the maddeningly elusive Higgs had been hunted by at least two generations of physicists who believed it would help shape our understanding of how the universe began and how its most elemental pieces fit together.

As the highly technical findings were announced by two independent teams involving more than 5,000 researchers, the usually sedate corridors of the European Center for Nuclear Research, or CERN, erupted in frequent applause and standing ovations. Physicists shed tears reflecting on the decades of work that brought them to this momentous occasion.