Why does electron capture produce a neutrino?

Question

Naomi Aronson · Accepted Answer

To maintain lepton numbers, electron capture generates an electron neutrino.

A proton in the nucleus of an atom can capture one of its inner electrons, resulting in the formation of a neutron and the emission of an electron neutrino. This process is known as electron capture.

#p + e⁻ → n + ν_e#

The Law of Conservation of Lepton Number is one of the regulations that must be observed in nuclear reactions; you are probably familiar with conservation laws like the Law of Conservation of Energy and the Law of Conservation of Momentum.

Electrons and neutrinos have spin ½ and are outside the nucleus, making them leptons; their lepton numbers are +1. A lepton is an elementary particle with spin ½ that is not subject to strong nuclear forces.

The strong nuclear force holds protons and neutrons together in the nucleus, and their lepton numbers are zero.

If the process were simply #p + e⁻ → n#, the sum of the lepton numbers would be +1 on the left and 0 on the right. Lepton numbers would not be conserved.

If an electron neutrino is emitted, as in #p + e⁻ → n + ν_e#, the sums of the lepton numbers are +1 on the left and +1 on the right. Lepton numbers are conserved.

This website, https://tutor.hix.ai has a very nice presentation and some very nice pictures.

Serenity Allen · Answer

undefined Electron capture produces a neutrino because during the process, a proton in the nucleus combines with an inner shell electron to form a neutron and a neutrino. This process conserves both energy and momentum, and the neutrino carries away some of the energy produced during the conversion of a proton to a neutron.