strange particle

noun

, Physics.

1. any elementary particle with a strangeness quantum number other than zero.

strange particle

1. Any of various unstable elementary particles, having a short half-life and a nonzero strangeness quantum number. Sigma and xi baryons, for example, are strange particles.

Word History and Origins

Origin of strange particle¹

First recorded in 1955–60; originally so called because of the anomalously long decay time of such particles