What is Beta decay?

Beta decay is the process where a nucleon decays into either an electron or a positron.

β decay (electron emission)

n → p + e + ν

A neutron decays into proton, an electron and an anti-neutrino.

β+ decay (positron emission)

p → n + e++ νe

A proton decays into a neutron, a positron and an electron neutrino.