Physicists have discovered two new members of a family of subatomic particles. The particles’ less-than-expected masses are forcing scientists to reconsider how some of nature’s most fundamental building blocks, quarks, interact.
Each of the newfound particles, designated respectively as Ds(2317) and Ds(2463), is a so-called Ds meson, which contains a charm quark and an antimatter quark called antistrange.