👉 The fourth-light particles, often referred to as "dark photons" or more precisely as "photon-like particles" within the framework of certain theoretical extensions to the Standard Model of particle physics, are hypothetical elementary particles that interact via the electromagnetic force but are distinct from the familiar photon, which mediates the electromagnetic force. These particles are postulated to arise in models that seek to unify fundamental forces or to explain phenomena not accounted for by the Standard Model, such as dark matter interactions. Unlike photons, which are massless and travel at the speed of light, fourth-light particles are expected to have a small but non-zero mass, making them detectable through their interactions with other particles, particularly in high-energy physics experiments. Their existence could provide insights into the nature of dark matter and the unification of forces, though they remain speculative until empirical evidence supports their presence.
