decuplet

A decuplet is a term used to denote a group of ten related items in a classification system. The most established usage is in particle physics, where a baryon decuplet denotes a ten-member multiplet of baryons with spin 3/2 that transform as a symmetric representation of the SU(3) flavor group. The members are arranged by strangeness and charge: Δ++ , Δ+, Δ0, Δ− ; Σ*+, Σ*0, Σ*− ; Ξ*0, Ξ*− ; and the Ω−. Their charges range from +2 to −1 and their strangeness from 0 to −3. The decuplet is characterized by approximately equal mass spacings and a common spin, reflecting the underlying flavor symmetry.

The decuplet was independently proposed in the 1960s by Murray Gell-Mann and Yuval Ne’eman as a natural outcome of SU(3) flavor symmetry. The predicted multiplet structure gained experimental support with the discovery of the Ω− baryon in 1964, which completed the decuplet. Mass patterns and decay properties of the members exhibit regularities consistent with the symmetry, though real-world effects such as hyperfine interactions introduce small splittings.

In literature, decuplet can also refer to a ten-line stanza in poetry, a form used in some traditions, though this usage is far less standardized than the scientific one. The term broadly conveys a set of ten related items, but in practice it is most often encountered in the context of particle physics.