Editing Beta decay (section)

==Helicity (polarization) of neutrinos, electrons and positrons emitted in beta decay==
After the discovery of parity non-conservation (see [[Beta decay#Non-conservation of parity|History]]), it was found that, in beta decay, electrons are emitted mostly with negative [[Chirality (physics)|helicity]], i.e., they move, naively speaking, like left-handed screws driven into a material (they have negative longitudinal [[Spin polarization|polarization]]).<ref>{{cite journal
 |last1=Frauenfelder |first1=H.
 |display-authors=etal.
 |year=1957
 |title=Parity and the Polarization of Electrons fromCo60
 |journal=[[Physical Review]]
 |volume=106 |issue= 2|pages=386–387
 |bibcode= 1957PhRv..106..386F
 |doi=10.1103/physrev.106.386
}}</ref> Conversely, positrons have mostly positive helicity, i.e., they move like right-handed screws. Neutrinos (emitted in positron decay) have negative helicity, while antineutrinos (emitted in electron decay) have positive helicity.<ref>{{cite book
 |last1=Konopinski |first1=E. J.
 |last2=Rose |first2=M. E.
 |year=1966
 |chapter=The Theory of nuclear Beta Decay
 |editor-last=Siegbhan |editor-first=K.
 |title=Alpha-, Beta- and Gamma-Ray Spectroscopy
 |volume=2
 |publisher=[[North-Holland Publishing Company]]
}}</ref>

The higher the energy of the particles, the higher their polarization.