Collider will be far more sensitive to anomalies that could lead to entirely new theories of the universe.

Ian Sample

Neutrinos are so tiny and inconspicuous that physicists believed for a long time they had no mass. Now, a massive device that scientists say will determine the mass of neutrinos has begun operation in Karlsruhe.

What is the exact mass of the three known kinds of neutrinos? Any answers? No? Well, don’t worry, because nobody knows. Not yet. Electron, muon and tau neutrinos are simply too difficult to grasp for scientists.

What would it say about the fundamental structure of the universe?

Physicists working at the Large Hadron Collider have made a major new detection of the famous Higgs boson, this time catching details on a rare interaction with one of the heaviest fundamental particles known to physics — the top quark.

The brief mingling of these incredibly rare encounters has provided physicists with important information on the nature of mass, and whether there is more to physics than the existing model predicts.

Results produced by the ATLAS and CMS experiments from the European Organization for Nuclear Research (CERN) help confirm the strength of the bond between Higgs bosons and top quarks.

The Higgs boson appeared again at the world’s largest atom smasher — this time, alongside a top quark and an antitop quark, the heaviest known fundamental particles. And this new discovery could help scientists better understand why fundamental particles have the mass they do.

When scientists at the Large Hadron Collider (LHC) first confirmed the Higgs’ existence back in 2013, it was a big deal. As Live Science reported at the time, the discovery filled in the last missing piece of the Standard Model of physics, which explains the behavior of tiny subatomic particles. It also confirmed physicists’ basic assumptions about how the universe works. But simply finding the Higgs didn’t answer every question scientists have about how the Higgs behaves. This new observation starts to fill in the gaps.

As the European Organization for Nuclear Research (CERN), the scientific organization that operates the LHC, explained in a statement, one of the most significant mysteries in particle physics is the major mass differences between fermions, the particles that make up matter. An electron, for example, is a bit less than one three-millionth the mass of a top quark. Researchers believe that the Higgs boson, with its role (as Live Science previously explained) in giving rise to mass in the universe, could be the key to that mystery. [Top 5 Implications of Finding the Higgs Boson ].

Scientists have produced the firmest evidence yet of so-called sterile neutrinos, mysterious particles that pass through matter without interacting with it at all.

The first hints these elusive particles turned up decades ago. But after years of dedicated searches, scientists have been unable to find any other evidence for them, with many experiments contradicting those old results. These new results now leave scientists with two robust experiments that seem to demonstrate the existence of sterile neutrinos, even as other experiments continue to suggest sterile neutrinos don’t exist at all.

That means there’s something strange happening in the universe that is making humanity’s most cutting-edge physics experiments contradict one another. [The 18 Biggest Unsolved Mysteries in Physics].

An experiment at the Fermi National Accelerator Laboratory near Chicago has detected far more electron neutrinos than predicted — a possible harbinger of a revolutionary new elementary particle called the sterile neutrino, though many physicists remain skeptical.