Potential New Particle Shows Up at the LHC, Thrilling and Confounding Physicists

A little wiggle on a graph, representing just a handful of particles, has set the world of physics abuzz. Scientists at the Large Hadron Collider (LHC) in Switzerland, the largest particle accelerator on Earth, reported yesterday that their machine might have produced a brand new particle not included in the established laws of particle physics known as the Standard Model. Their results, based on the data collected from April to November after the LHC began colliding protons at nearly twice the energy of its previous runs, are too inconclusive to be sure—many physicists warned that the wiggle could just as easily represent a statistical fluke. Nevertheless, the finding has already spawned at least 10 new papers in less than a day proposing a theoretical explanation for the particle, and has the halls and blackboards of physics departments around the world churning.

“This is something that we’ve been waiting for for a long time,” says Adam Falkowski, a physicist at the Institute of Theoretical Physics in Warsaw and a member of the CERN Theory Group. “Of course we are aware this could be nothing. But for my generation, this is the first time there is a very large, quite reliable signal of physics beyond the Standard Model, so it’s definitely very exciting.” Of course, others echoed the usual refrain of caution: “Extraordinary claims require extraordinary evidence, and this is not that,” Columbia University physicist Peter Woit wrote on his blog.

If the LHC truly has seen a new particle, however, the question looming large is: What is it? From its signature at the LHC, the particle must weigh roughly 750 giga-electron volts (GeV), around 750 times the mass of the proton, and would fall into the class of bosons, meaning its spin has an integer value. Some theorists say the newcomer looks like a heavier cousin of the Higgs boson, which similarly first showed up at the LHC as a highly intriguing blip in the data about four years ago. Or it could be a kind of portal particle into the dark matter sector—because this particle decays almost immediately, on its own it cannot account for the invisible matter that seems to be ubiquitous in space, but it may be a messenger that communicates with the dark matter particle, theorists suggested. Another hypothetical alternative is that it is a graviton, the predicted carrier particle for the force of gravity.

Continue reading the entire article by clicking the name of the source below.