Sigma baryon

The third quark can hence be either a strange (symbols
Σ⁺
,
Σ⁰
,
Σ⁻
), a charm (symbols
Σ⁺⁺
_c,
Σ⁺
_c,
Σ⁰
_c), a bottom (symbols
Σ⁺
_b,
Σ⁰
_b,
Σ⁻
_b) or a top (symbols
Σ⁺⁺
_t,
Σ⁺
_t,
Σ⁰
_t) quark. However, the top sigmas are expected to never be observed, since the Standard Model predicts the mean lifetime of top quarks to be roughly 5×10⁻²⁵ s. This is about 20 times shorter than the timescale for strong interactions, and therefore it does not form hadrons.

List

The symbols encountered in these lists are: I (isospin), J (total angular momentum), P (parity), u (up quark), d (down quark), s (strange quark), c (charm quark), t (top quark), b (bottom quark), Q (electric charge), S (strangeness), C (charmness), B′ (bottomness), T (topness), as well as other subatomic particles (hover for name).

Antiparticles are not listed in the table; however, they simply would have all quarks changed to antiquarks (and vice versa), and Q, B, S, C, B′, T, would be of opposite signs. I, J, and P values in red have not been firmly established by experiments, but are predicted by the quark model and are consistent with the measurements.

JP = ⁠1/2⁠+ sigma baryons

^† ^ The standard model predicts that this particle cannot exist.
^[a] ^ PDG reports the resonance width (Γ). Here the conversion τ = ⁠ħ/Γ⁠ is given instead.
^[b] ^ The specific values of the name has not been decided yet, but will likely be close to
Σ
_b(5810).

JP = ⁠3/2⁠+ sigma baryons

^† ^ The standard model predicts that this particle cannot exist.
^[c] ^ PDG reports the resonance width (Γ). Here the conversion τ = ⁠ħ/Γ⁠ is given instead.