What is a Lepton?

A lepton is a fermion with a spin / 2 that does not participate in strong interactions. Lepton includes electrons, muons, particles and their corresponding neutrinos ( _e , and and their antiparticles). The electron e-, - ^, and ^- particles have masses of 0.51 megV, 105.66 megV, and 1,776.99 megV, respectively, and they all carry a unit of negative charge. Their antiparticles e ⁺ , ⁺ and ⁺ carry a positive charge of one unit. Neutrinos and their antiparticles are not charged and are neutral particles. Experimental results in recent years have shown that neutrinos have a non-zero static mass. ^[1]

Experimental and theoretical research on the basic components of matter and their interactions has revealed many mysteries of the particle physics world. We now know that there are two major families of basic bricks that make up everything: Lepton and

There are six types of particles in the lepton family

Lepton all involved

In 1962, it was found experimentally that there are two kinds of neutrinos _e and , which are associated with electrons and _muons , respectively. Therefore, the conservation of lepton numbers is decomposed into electron numbers (e ^- and _e particle number minus e ⁺ and The number of _e particles) and the number of muons ( ^- and particles minus ⁺ and particles) are conserved, respectively. In 1975, M. Pell et al. Discovered a new lepton in the e ⁺ e ^- collision experiment, which is negatively or positively charged and decays into a muon or an electron and two neutrinos. Its mass is 1,776.99 megaelectron volts, which is nearly twice the mass of a proton, so it is also called a lepton. In 2000, neutrinos corresponding to particles were found experimentally. Similarly, the lepton number is conserved in all processes where lepton participates. Except for particles, the properties of the first two types of leptons (e, _e and , ) have been fully studied. Their properties are very similar, only the masses are very different. The phenomenon is explained by particle physics. An important issue in theory that has yet to be resolved. ^[1]