neutrontoproton

The term neutrontoproton is not a standard label in physics; the process it describes is widely referred to as neutron beta decay or neutron-to-proton conversion. In this process, a neutron transforms into a proton through the weak nuclear interaction, emitting an electron and an electron antineutrino. The canonical reaction is n → p + e− + ν̄e.

Mechanism and energetics: The transformation proceeds via a charged-current weak interaction mediated by a W− boson. The neutron is heavier than the proton by about 1.293 MeV, which yields a decay energy (Q value) of roughly 0.782 MeV after accounting for the electron rest mass. The emitted electron can have kinetic energy up to about 0.782 MeV, with the remainder shared with the antineutrino and the recoiling proton. The free neutron has a mean lifetime of about 880 seconds, or roughly 14.7 minutes.

In nuclei: Within a nucleus, a neutron can convert to a proton, increasing the atomic number by one and changing the element. This beta-minus decay occurs in neutron-rich nuclei and competes with other decay modes, with observed half-lives ranging from milliseconds to billions of years depending on energy release and nuclear structure. In various environments, neutron-to-proton conversions influence nucleosynthesis and the chemical makeup of matter.

Context and significance: Neutron-to-proton conversion is a cornerstone of the weak interaction and beta decay studies. It informs measurements of weak-force parameters and neutrino properties. Historically, neutron beta decay helped establish the theory of weak interactions in the 1930s, contributing to the development of the electroweak framework.