Lepton (noun, “LEP-tawn”)
A lepton is a type of elementary particle.
An elementary particle is one that scientists believe is not made of anything smaller. Besides leptons, these include quarks and bosons.
Leptons come in six types, or flavors. (Yes, that’s really what physicists call them.) The best-known of these is the electron. Two others are muons and tauons. The remaining three are flavors of neutrinos: electron neutrinos, muon neutrinos and tau neutrinos. You can think of them as neutrino versions of the first three lepton types.
Two things set leptons apart from other elementary particles.
The first involves a force scientists call the strong force. The strong force causes particles to glom together, forming larger clumps. It’s what holds protons and neutrons together in an atom’s nucleus. It’s also what holds quarks together to make up protons and neutrons.
Leptons don’t undergo strong force. For that reason, leptons don’t have the same groupwide tendency to bunch together like quarks do. If leptons form larger particles, some other force must hold things together.
The second thing all leptons share involves something called spin. Spin is a quantum feature of subatomic particles. All leptons share the same spin pattern. That pattern is called a half-integer spin. Quarks have half-integer spins, too. Bosons — another type of elementary particle — have integer spins. Particles with different spins interact with matter and magnetic fields in different ways.
Outside these two common traits, lepton flavors vary a lot. Some are much heavier than others. For example, a single tau weighs more than 3,000 electrons. Some leptons carry an electrical charge, and some do not. Charged leptons include electrons, tauons and muons. The three neutrinos have no electrical charge. Being neutral allows them to zip through most matter. That includes our bodies and the Earth itself.
In a sentence
Scientists hope forests can help them detect elusive, high-energy leptons called neutrinos.
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