The antiparticle mathematical world is the same as the particle world with characteristic quantum numbers in the negative, so when particle meets antiparticle they can disappear. The anti electron neutrino carries a negative electron lepton number. That is the way for lepton numbers to disappear. The positron has a negative electron number, and when they meet they disappear into two photons. A neutron is a particle very similar to the proton, they are bot hadrons, which means that they are made by quarks. Thus rose the concept of lepton number conservation, : an electron cannot just disappear or appear (as is the case in muon decay, which leads to the world of antiparticles:įor every particle in the particle table, there exists an antiparticle, which has the opposite quantum numbers, for the electron it is the positron.( for the proton ,which is composed out of quarks, the antiproton). Infact the neuron is a cell developed to transmit electrochemical signals and it is made of thousands of protons, they are on totally different scales. They could not be the same because to explain the the decay of the muon to an electron, one needed two neutral particles, an electron antineutrino and a muon neutrino. Then other particles were discovered later, like the muon and the tau leptons, also necessitated the existence of a muon neutrino and a tau neutrino. So they defined it as an electron neutrino. Here is how it was proposed and then discovered: energy and momentum would not be conserved in the decay of the neutron to a proton and an electron, it seemed that a neutral particle was taking away energy and momentum. This led to the mathematics of special relativity, where particles can decay to lower mass particles.Ĭonservation of energy and momentum still holds in special relativity, and the decays of particles seen in cosmic and laboratory experiment led to the necessity of defining an electron neutrino, as well as two other neutrinos. It was thought in classical physics that mass was also conserved, but this proved to be wrong at the level of studying the interactions of nuclei, of which all macroscopic masses are composed. When a neutron decays to a proton and an electron, it must also create an anti-electron neutrino, conserving both lepton number (the total number of leptons minus the total number of anti-leptons. Energy is conserved, the sum of all energies is conserved in an isolated system, as well as momentum. We all were once new to nuclear physics and then to particle physics that evolved from nuclear physics.īasic rules in physics are classified into conservation laws. Please keep it simple so that a grade 11 kid, new to nuclear physics would understand.

Neutrino vs neutron