sigma hyperon

sigma hyperon

[′sig·mə ′hī·pə‚rän]
(particle physics)
The collective name for three semistable baryons with charges of +1, 0, and -1 times the proton charge, designated Σ+, Σ0, and Σ-, all having masses of approximately 1193 megaelectronvolts, spin of ½, and positive parity; they form an isotopic spin multiplet with a total isotopic spin of 1 and a hypercharge of 0.
Any baryon belonging to an isotopic spin multiplet having a total isotopic spin of 1 and a hypercharge of 0; designated ΣJ P (m), where m is the mass of the baryon in megaelectronvolts, and J and P are its spin and parity; the Σ3/2+(1385) is sometimes designated Σ*.
References in periodicals archive ?
Mathematicians spend their time playing with triangles and hexagons; physicists spend their time playing with lambda hyperons and sigma hyperons.