Meganeutron

Meganeutron is a hypothetical baryonic state proposed in certain speculative theories to denote a heavy, neutron-like particle with baryon number 1 and electric charge zero. It would resemble a neutron in its low-energy quantum numbers while possessing a substantially larger rest mass. No experimental evidence has established its existence.

In one interpretation, a meganeutron is a single baryon with mass several times that of the neutron, a half-integer spin, and neutral charge. In another view, it represents a bound multi-neutron cluster stabilized by a hypothetical new strong interaction beyond ordinary quantum chromodynamics. In both cases, lifetimes range from short-lived resonances to potentially long-lived states depending on model parameters.

Research on meganeutrons resides in speculative extensions of hadron spectroscopy, neutron-rich matter, and beyond-Standard-Model scenarios. Production mechanisms proposed include high-energy hadron collisions or exotic processes in dense astrophysical environments. Experimental searches—particle accelerators, nuclear reaction studies, and astrophysical observations—have thus far yielded no conclusive signals. Consequently, meganeutrons remain hypothetical and are used primarily to explore the limits of baryon structure and dense-matter physics.