Leptons are particles that have spin quantum number 1/2 and don't experience the strong force. (leptons include: electrons, muons, and neutrinos)
Antileptons are antimatter. Like all antimatter, they are identical to their matter counterparts in mass and size, but opposite in magnetic and electric properties. If antimatter contacts its matter counterpart, they will both be destroyed and create energy. (antileptons include: positrons, antimuons, and antineutrinos)
Leptons are part of a larger group, called fermions (particles with spin quantum numbers that are odd multiples of 1/2 (1/2, 3/2, 5,2, etc.) and therefore obey the pauli exclusion principle) that include protons and neutrons as well as leptons. Leptons differ from other fermions in that they are not made up of smaller particles called quarks (quarks are the particles that experience the strong force ... this is why leptons do not experience the strong force). Fermions that ren't leptons include protons, neutrons, and quarks.
Fermions differ from another type of particles, called bosons (such as photons and mesons), because bosons have integer (1, 2, 3, etc.) spin quantum numbers. and don't obey the pauli exclusion principle.
The less technical answer:
Most of the particles that we normally think of as particles are either leptons or are made up of smaller particles called quarks. (the most well-known lepton is the electron, the most well known non-lepton fermions are protons and neutrons)
Antileptons are the same in size and mass but opposite in electric and magnetic properties to leptons. When the two get together, they destroy each other and produce energy. (the most well-known antilepton is the positron (anti-electron) ... it is used in medical PET (positron emission tomography) scans)
[This message was edited by methos5000 on 04-11-03 at 04:39 PM.]
