Helicity

1. Helicity is a combination of the spin and the linear motion of a subatomic particle.
2. Helicity is the projection of the spin onto the direction of momentum.

Helicity – helicity of the neutrino was experimentally measured in 1958 by a group of M. Goldhaber. In this experiment, the task of the direct determination of the helicity of the neutrino has been reduced to the determination of the photon helicity, who participated along with the neutrino in the process of radioactive decay of a nucleus (_63^152)Eu.

Sources:

Словник Webster's Dictionary https://www.merriam-webster.com/

MacMillan Dictionary https://www.macmillandictionary.com/dictionary/british

Прикладна фізика. Українсько-російсько-англійський тлумачний словник: У 4 т., Т. 4: С — Я / уклад.: О. Т. Богорош, С. О. Воронов, О. Г. Шайко-Шайковський, В. З. Маїк, М. Ф. Ясінський. — Львів : Укр. акад. друкарства, 2015. 387c.