Beta-plus decay
= Beta-plus decay
{title2=${}^A_ZX\longrightarrow{}^A_{Z-1}Y+e^++\nu_e$}
An energetically allowed weak nuclear transition converts a proton into a neutron, emitting a positron and electron <neutrino>. Positron annihilation deposits additional electromagnetic energy, while the <neutrino> can escape. These transitions are steps of the <CNO cycle> and the pp III branch; an isolated free proton cannot undergo this decay.