S. Jia

Inside the accelerator, particles collide, and for a fleeting moment a B meson is born — a heavy particle that lives for less than a billionth of a second. Usually, it decays into a shower of debris, but sometimes it transforms into just two particles: a muon and a neutrino. This rare path is like a lottery where the winning ticket appears once in every two million draws.

At Japan's KEK laboratory, electrons and their antimatter counterparts, positrons, collide inside the Belle II detector. In such collisions, new particles are born for a fleeting moment. Among them is J/ψ, a bound state of a charm quark and its antiquark.

The proton isn't a solid ball; it's more like a tight tangle of quarks and gluons. Gluons are the particles that carry the strong force — a kind of glue that holds quarks together. But this glue doesn't just connect; it presses. In the J/ψ-007 experiment at Jefferson Lab, a beam of photons was aimed at protons.