6 articles tagged with beta decay.
Neutrinos are produced any time a weak nuclear interaction takes place — which means they pour out of the Sun, atomic nuclei, the atmosphere, particle accelerators, supernovae, and the Big Bang itself. Here is a tour of every way a neutrino comes into existence, and roughly how many you encounter from each.
Enrico Fermi's 1933 paper introduced the four-fermion interaction that explained beta decay and named the neutrino. Why this is still the conceptual foundation of weak-interaction physics.
In a tired old building on a small street in Rome in the 1930s, a young Enrico Fermi and a handful of colleagues built the theory of beta decay, discovered slow neutrons, and named the neutrino. Then most of them left.
Neutrinos and antineutrinos have opposite lepton number and opposite helicity. Neutrinos are produced together with positrons in beta-plus decay; antineutrinos with electrons in beta-minus decay. Whether they are actually distinct particles or two faces of the same one is still an open question.
Beta decay emits a neutrino; neutrino capture absorbs one. They are time-reversed counterparts of the same weak interaction, and the cross section for capture is calculably tiny compared to the rate of beta decay. Both processes are central to neutrino physics and to the cosmic neutrino background hunt.
In a letter to a physics conference he skipped to attend a ball, Wolfgang Pauli proposed a particle no one expected to detect — and saved the law of energy conservation.
