Parvoon

Parvoon is a hypothetical elementary particle posited in certain extensions of the Standard Model of particle physics. The name, derived from the Latin parvus meaning small, signals its proposed light mass relative to many familiar particles. In many models, parvoons belong to a hidden or dark sector that interacts feebly with known particles through a portal, such as kinetic mixing with the photon or coupling to the Higgs field.

Proposed properties vary by model. Parvoons are typically described as bosons with relatively small mass and with couplings that are highly suppressed, leading to long lifetimes or invisible decays. Depending on the framework, they may carry a U(1)′ gauge charge or be scalar mediators that communicate between the visible sector and dark matter. Their production could occur in high-energy collisions, meson decays, or astrophysical processes, and their decay products might include leptons, photons, or invisible final states.

Why it matters: if real, parvoons could help explain dark matter interactions, anomalies in precision measurements, or unexplained astrophysical signals. They also illustrate the broader theoretical idea of hidden sectors and portal interactions that extend beyond the Standard Model.

Experimental status: to date there is no confirmed observation of a parvoon. Experiments in collider physics, fixed-target facilities, and astrophysical surveys have constrained possible masses and couplings, but large regions of parameter space remain open. Ongoing and planned experiments aim to improve sensitivity to feeble signals predicted by parvoon models.

See also: dark photon, hidden sector, portal interactions, beyond the Standard Model.