The standard model of particle physics is often illustrated as a simple grid showing the 17 basic particles (shown above). But an alternative way of visualizing it reveals the complex rules that govern how the particles and forces interact.
This article is part of a special series on the standard model, in which we explore:
The conventional grid shows three generations of quarks (which feel the strong force) and leptons (which don’t). Then there are the bosons that mediate three of the fundamental forces of nature – the strong and weak nuclear forces and electromagnetism. But it doesn’t give us the full picture.
For one, there are parts missing, like the fact that most particles can occur in two forms of a property called handedness: right-handed and left-handed. It also tells us nothing about which particles feel which forces. There are mysteries it glosses over, too, like the fact there are no right-handed neutrinos, at least that we know of. “The standard grid, as lovely as it is, looks finished,” says a theoretical physicist at the Fermi National Accelerator Laboratory in Illinois. “But the standard model is not finished.”
The physicist mentioned above, Chris Quigg, believed that a new way was needed to visualize the theory that reflected its complexity. In 2005, he introduced the double simplex (shown above). It consists of two pyramids connected by the Higgs boson. One half represents left-handed particles and the other represents right-handed ones. Each vertex of the pyramid represents a generation of particles, with each generation being more massive than the last.