leptonantals

Leptonantals are a hypothetical class of composite particles proposed in speculative extensions of the Standard Model. In these frameworks, a new confining interaction binds leptons to light hidden-sector states, producing neutral bound configurations called leptonantals. The idea is to explore connections between the visible lepton sector and a hidden sector while remaining consistent with existing experimental constraints.

Constituents and classification are model dependent. A leptonantal is typically described as a bound state formed from a Standard Model lepton (electron, muon, or tau) together with a hidden-sector partner, resulting in an overall electrically neutral particle. The spectrum may include scalar, pseudoscalar, or fermionic states, depending on the spins and couplings of the constituents. Interactions with known particles can occur through portal couplings or kinetic mixing, allowing leptonantals to communicate weakly with the Standard Model.

Production and decay channels are explored in collider and astrophysical contexts. Possible production mechanisms include high-energy collisions that create a leptonantal pair or the decay of heavier states. Decay channels vary by model but commonly involve lepton pairs, photons, or transitions to invisible hidden-sector states. Lifetimes can span from prompt decays to long-lived states, making experimental signatures diverse.

Status and prospects: leptonantals remain theoretical and unobserved. Experimental efforts constrain their masses and couplings through precision measurements, collider searches, and indirect astrophysical observations. If real, they could influence lepton phenomenology, provide portals to hidden sectors, or contribute to dark matter scenarios.

See also leptonium, hidden sector, exotic hadrons, dark matter.