The physics lab home to the world’s largest atom smasher announced Tuesday the observation of three new “exotic particles” that could provide clues about the force that binds subatomic particles together. The observation of a new type of pentaquark and the first duet of four quarks at CERN, the site of the Geneva-based Large Hadron Collider, offers a new perspective on assessing the “strong force” that holds the nuclei of atoms together. Most exotic hadrons, which are subatomic particles, consist of two or three elementary particles known as quarks. The strong force is one of the four known forces in the universe, along with the “weak force” — which applies to the breaking apart of particles — as well as the electromagnetic force and gravity. The announcement comes amid a flurry of activity this week at CERN: Also on Tuesday, the LHC’s underground ring of superconducting magnets that propel infinitesimal particles along a 27-kilometer (about 17-mile) circuit at nearly the speed of light began smashing them together again. . Collision data is collected by high-tech detectors along the circular route. The so-called “Run 3” of the collisions, ending a three-year pause for maintenance and other checks, operates at an unprecedented energy of 13.6 trillion electron volts, which will offer the prospect of new discoveries in particle physics. CERN scientists have hailed the smooth start of what is expected to be nearly four years of operation in “Run 3” — the third time the LHC has run collisions since its debut in 2008. A day earlier, CERN celebrated 10 years since the confirmation of the Higgs boson, the subatomic particle that is central to the so-called Standard Model that explains the basics of particle physics.
