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Systematics of beta decay (view source)
Revision as of 06:10, August 20, 2019
, 06:10, August 20, 2019→Conservation laws
When dealing with beta transformations, one needs to take note of various conservation laws. (For alpha and gamma transformations, particles don't change, so these issues don't come up.)
When dealing with beta transformations, one needs to take note of various conservation laws. (For alpha and gamma transformations, particles don't change, so these issues don't come up.)
*Charge - this is the electric charge. So a neutron, with zero charge, can decay into a proton (+1), and electron (-1), and a neutrino (zero).
*Charge - this is the electric charge. So a neutron, with zero charge, can decay into a proton (+1), and electron (-1), and a neutrino (zero).
*Baryon number - Baryons are "big" nucleons. For our purposes, they are protons and neutrons. They can't just go away. Nor can the transform into their antiparticles. (A proton and antiproton annihilating each other would satisfy this, since the baryon numbers are +1 and -1, but that transformation is beyond the scope of this article.)
*Baryon number - Baryons are "big" nucleons. For our purposes, they are protons and neutrons. They can't just go away. Nor can they transform into their antiparticles. (A proton and antiproton annihilating each other would satisfy this, since the baryon numbers are +1 and -1, but that transformation is beyond the scope of this article.)
*Lepton number. The lepton numbers can be thought of as "electron-ness", "mu-ness", and "tau-ness". Electrons and positrons have electron-ness of +1 and -1 respectively (and zero for the other two). Here is where the neutrinos come into play. An electron neutrino has an electron-ness of +1, while and anti-neutrino has -1. That's why the neutron-to-proton-and-electron transformation needs to create the antineutrino to carry off the -1, compensating for the +1 of the electron.
*Lepton number. The lepton numbers can be thought of as "electron-ness", "mu-ness", and "tau-ness". Electrons and positrons have electron-ness of +1 and -1 respectively (and zero for the other two). Here is where the neutrinos come into play. An electron neutrino has an electron-ness of +1, while and anti-neutrino has -1. That's why the neutron-to-proton-and-electron transformation needs to create the antineutrino to carry off the -1, compensating for the +1 of the electron.