# Physics:Theta meson

Short description: Hypothetical form of quarkonium
Composition tt bosonic strong, weak, gravitational, electromagnetic hypothetical self 0 e 0 0 −1 −1

The theta meson (θ)[1] is a hypothetical form of quarkonium (i.e. a flavourless meson) formed by a top quark (t) and top antiquark (t). As a P-odd and C-odd tt state, it is analogous to the ϕ (ss), J/ψ (cc) and ϒ (bb) mesons. Due to the top quark's short lifetime, the theta meson is expected to not be observed in nature.[2]