Fotont

Fotont is a hypothetical elementary particle proposed in certain extensions of electromagnetism as the quantum of a second, light-like gauge field. In these models, the fotont is not the photon, but a distinct spin-1 boson associated with an additional U(1) gauge symmetry. It may interact with ordinary matter through kinetic mixing with the photon, yielding very weak or effectively invisible couplings.

In theoretical settings, the fotont is often discussed within hidden-sector or dark-sector frameworks. Depending on the model, the fotont can be massless or acquire a small mass through symmetry breaking, leading to dispersion relations similar to Proca-type behavior. Its couplings and possible decay channels are highly model-dependent; however, in many proposals the fotont is long-lived on laboratory scales and difficult to detect directly.

Relation to photons: Photons are the quanta of the visible electromagnetic field, while fotonts would be quanta of an auxiliary gauge field. Through kinetic mixing with the photon, fotonts could induce tiny deviations in electromagnetic phenomena, such as small corrections to Coulomb’s law, anomalous light propagation, or additional channels in particle decays and beam-dump experiments. There is currently no experimental evidence for fotonts, and constraints arise from precision quantum electrodynamics tests, astrophysical observations, and dedicated hidden-photon searches.

Status and outlook: Fotonts remain speculative. Their discovery would indicate new gauge symmetries and hidden sectors with potential implications for dark matter and physics beyond the Standard Model. Ongoing experiments in precision optics, astrophysical data analysis, and targeted hidden-photon searches continue to probe their possible parameter space.