Hunting Dark Photons with a Mirror Telescope express
The universe is held together by an invisible scaffolding of dark matter. Part of it could be dark photons, ghostly copies of light that pass right through matter. The Dandelion experiment turned a spherical mirror into a super-sensitive ear: it gathers dark photons and translates them into the language of radio waves. 221 detectors chilled nearly to absolute zero listened for that whisper for 1480 minutes.
The trouble is, the whisper gets drowned out by a roar — thermal noise from the room and electronics. Physicists used spectral analysis as noise cancellation: they recorded the background from sensors not aimed at the target and subtracted it from the main data.
The silence remained absolute. But it’s not useless: the experiment, for the first time using quantum detectors for photometry, set the tightest limit yet on how likely dark photons are to turn into ordinary light in the mass range of 0.6–1.4 meV.
A dark photon with a mass of 1 meV is half a million times lighter than an electron — the lightest particle with nonzero mass.