The search continues, only our head is in the clouds

The axion is a hypothetical elementary particle postulated by the Peccei–Quinn theory in 1977 to resolve the strong CP problem in quantum chromodynamics(QCD). If axions exist and have low mass within a specific range, they are of interest as a possible component of cold dark matter.

The experiment conducted by Rizzo’s team differed from the approach of the Italian researchers in the fact that at the end of a vacuum chamber, an aluminium plate was placed^[6] to prevent photons from an adjacent laser from passing through the plate, where axions would simply pass through the plate and be converted back into photons,^[6] and were able to observe a small-portion of the supposed-converting particles—to the number of 4×10²² photons.^[6]

A term analogous to the one that must be added to Maxwell’s equations^[15] also appears in recent theoretical models fortopological insulators.^[16] This term leads to several interesting predicted properties at the interface between topological and normal insulators.^[17] In this situation the field θ describes something very different from its use in high-energy physics.^[17]

Godspeed