dark photon

History

The idea of the dark photon emerged at the end of the 20th century when physicists were looking for ways to explain dark matter.

How it works

If dark photons exist, they can occasionally mix with ordinary photons, becoming briefly visible. It's like two parallel roads with very rare pedestrian crossings.

History

The idea of the dark photon emerged at the end of the 20th century when physicists were looking for ways to explain dark matter.

How it works

If dark photons exist, they can occasionally mix with ordinary photons, becoming briefly visible. It's like two parallel roads with very rare pedestrian crossings.

History

The concept emerged in the 1980s as a byproduct of grand unified theories. In the 2008–2010s, interest revived thanks to experiments searching for light dark photons (LSND, MiniBooNE) and anomalies in cosmic rays. Leading laboratories, such as CERN (NA64) and SLAC (HPS), are actively searching.

How it works

If the dark photon is light (meV–MeV), it could manifest as an additional radiation source or affect star cooling. In experiments, it is searched for via radiation processes (e.g., e⁺e⁻ → γ γ', where the signal is a single photon with missing energy) or through resonant conversion of ordinary photons into dark ones in vacuum chambers (the "light through a wall" scheme). Heavier dark photons decay into charged leptons and can be detected by colliders.

Open problems & fun facts

What is the mass of the dark photon?; Does it make up all dark matter or only part of it?; Does it explain the muon magnetic moment anomaly?

💡 If the dark photon exists, a powerful laser could be used to "illuminate" the hidden sector and observe the creation of dark particles.