Scientists around the globe are revved up with excitement as the world’s biggest atom smasher — best known for revealing the Higgs boson four years ago — starts whirring again to churn out data that may confirm cautious hints of an entirely new particle. Such a discovery would all but upend the most basic understanding of physics, experts say.

The European Center for Nuclear Research, or CERN by its French-language acronym, has in recent months given more oomph to the machinery in a 27-kilometer (17-mile) underground circuit along the French-Swiss border known as the Large Hadron Collider. In a surprise development in December, two separate LHC detectors each turned up faint signs that could indicate a new particle, and since then theorizing has been rife. FULL REPORT