Beta Decay - Neutrons, AntiNeutrons, Neutrinos, Electron Anti-Neutrinos

[Sorcerer]

Why is it that the decay product of a normal Neutron is called anti matter, ie the electron anti neutrion, which the decay product of antimatter, the antineutron is normal matter, ie the neutrino.

What makes a neutrino a normal particle and an electron anti neutrino an anti particle?

Sorry, wikipedia is my only source. http://en.wikipedia.org/wiki/Antineutron

Should the entry also include a decay where a antineutrino is produced for conservation of energy?

Edited November 6, 2014 by Sorcerer

[imatfaal]

Why is it that the decay product of a normal Neutron is called anti matter, ie the electron anti neutrion, which the decay product of antimatter, the antineutron is normal matter, ie the neutrino.

 

What makes a neutrino a normal particle and an electron anti neutrino an anti particle?

 

Sorry, wikipedia is my only source. http://en.wikipedia.org/wiki/Antineutron

 

Should the entry also include a decay where a antineutrino is produced for conservation of energy?

 

The electron neutrino and anti-neutrino are uncharged and this raises two points. Firstly, They could be the same particle - a Majorana particle - although at present all the neutrinos we observe have a left handed helicity and all the anti-neutrinos have a right handed helicity. Secondly as they are neutral we get to decide which is which - and for symmetry reasons it was decided that in beta decay you got an electron and an anti-neutrino but in beta plus you get a positron and a neutrino; it basically means that lepton number is conserved. At start you have no leptons - then you have an electron (lepton number 1) so you balance it out with an anti-neutrino (lepton number -1)

[mathematic]

The simple answer is maintaining a count. Neutron decays into proton + electron + neutrino. To keep the matter count the same the neutrino is considered antimatter ro balance the two matter particles.