Sneutrino

Part of speech: noun

Definitions

1. A hypothetical elementary particle in particle physics that is the supersymmetric partner of a neutrino, predicted to have spin zero
2. A theoretical spin-zero particle proposed by supersymmetry theories as the counterpart of the neutrino, not yet observed in experiments
3. In supersymmetric physics, a postulated scalar particle paired with a neutrino, whose existence would extend the Standard Model

Etymology: The sneutrino is a hypothetical particle, and its name is a plain piece of particle-physics shorthand rather than a story of coinage. It is formed by attaching the prefix "s-" to "neutrino," the name for the nearly massless, electrically neutral particle first proposed by Wolfgang Pauli in 1930. The "s-" marks the partner particle's relation to its neutrino counterpart: in supersymmetry, every known particle is paired with a partner whose spin differs by half a unit, and the partner of a neutrino is called a sneutrino. The prefix follows a pattern used across the supersymmetry literature, where partners of fermions take an "s-" name. The partner of the electron is the "selectron," and the partner of the quark becomes the "squark," so the sneutrino sits within a consistent naming scheme. Its existence has not been confirmed experimentally, so the word names a theoretical object rather than a detected one.