Neutronenes

Neutronene is a hypothetical subatomic particle proposed in speculative physics contexts to extend the standard model. In common variants it is described as a neutral, fermionic particle with a baryon number of one and a mass close to that of the neutron. Its exact properties depend on the model, but typical assumptions include zero electric charge, spin 1/2, and interactions that are weak or highly suppressed with ordinary matter. A key distinction among proposals is whether the neutronene is a genuine bound state of quarks (a heavy baryon) or an effective degree of freedom arising from new interactions with a hidden sector. Some models allow for strong interactions in high-density environments, while others treat it as primarily coupled through the weak force or gravity.

Motivations for considering neutronenes include attempts to address anomalies in neutron decay measurements, as components of dark matter scenarios with portal couplings, or as test cases for new symmetries and baryon-number dynamics. The predicted lifetime and decay channels are highly model dependent; some variants envision a long-lived or stable particle, others predict decays into lighter standard-model particles via weak processes.

Experimental searches have not found evidence for neutronenes. Constraints come from precision neutron decay studies, nuclear binding and reaction data, and searches for exotic baryons in collider and reactor experiments; together they limit possible production rates, masses, and lifetimes. As a result, neutronenes remain speculative and are primarily discussed in theoretical or science-fiction contexts.

See also: exotic baryons, hidden sectors, neutron lifetime anomaly.