Belle II Detector Produces World’s Most Precise Measurements of Subatomic Particle Lifetimes

The Science

Scientists believe that subatomic particles called quarks and leptons (such as electrons and neutrinos) are the building blocks of all visible matter in the universe. However, at very high energy levels, similar to the conditions soon after the Big Bang, scientists can produce particles containing different types (or flavors) of quarks, although they decay very quickly. The new Belle II experiment recently made a world-leading measurement of the lifetime of one such particle. This demonstrates the experiment’s ability to make the extremely precise measurements. Scientists need this level of precision in their quest to discover new particles and interactions.

The Impact

Researchers can use the Standard Model of Particle Physics to make very accurate predictions about how subatomic particles interact and decay. However, there are gaps in the Standard Model that indicate other particles and interactions that have never been observed. Researchers want to fill these gaps to better explain how our universe developed. Many extensions of the Standard Model attempt to resolve these inconsistencies. However, these extensions rely on approximations of the complicated interactions of subatomic particles. Those approximation methods can also be used to predict particle lifetimes. Precise measurements of particle lifetimes from the Belle II experiment therefore provide stringent tests of theoretical predictions beyond the Standard Model.

Summary

Using the new, state-of-the-art detector, the Belle II experiment reported a world-leading measurement of the Λ+