On the right, the gauge bosons, which mediate the three fundamental quantum forces of our Universe, are illustrated. There is only one photon to mediate the electromagnetic force, there are three bosons mediating the weak force, and eight mediating the strong force. This suggests that the Standard Model is a combination of three groups: U(1), SU(2), and SU(3), whose interactions and particles combine to make up everything known in existence. Despite the success of this picture, many puzzles still remain. (Credit: Daniel Domingues/CERN)

Particle physics finally charts a healthy path forward

A great many cosmic puzzles still remain unsolved. By embracing a broad and varied approach, particle physics heads toward a bright future.

Just a decade ago, the field of particle physics looked to be in a state of chaos. The Large Hadron Collider had recently turned on, and although they found the Higgs boson — the final undiscovered particle predicted by the Standard Model — it failed to turn up any evidence for any of the other leading theories that would take us beyond the Standard Model. Fermilab, the prior leader in the energy frontier, shut down its main accelerator permanently, and puzzles such as:

• the origin of neutrino mass,
• the nature of dark matter,
• and the origin of the matter-antimatter asymmetry,

seemed to be stagnating, with little progress to show on either the experimental or theoretical fronts.

Moreover, particle physicists themselves seemed to be bickering and in disarray as to what they should do next. Would there be enough value to justify a new, more powerful accelerator than the Large Hadron Collider? How should we be probing the behavior of neutrinos in order to understand neutrino mass? Are we taking…