|Interactions||strong, weak, gravitational, electromagnetic|
|electric charge||0 e|
The theta meson (θ) 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.
Original source: https://en.wikipedia.org/wiki/Theta meson. Read more