Radical photon idea could rewrite standard model of particle physics

If photons possess more quantum states than expected, it would overhaul our understanding of all particle physics – and now physicists have identified a way to test this radical idea in an experiment.

Certain elementary particles have a property called spin. For particles of light, or photons, spin can be in one of two potential states, which manifests as the light being polarised in one of two directions. But what if photons had more options – what if they could be in any of an infinite number of spin…