Question

Explain the terms : a) leptons : electron , electron nutrino , tau , tau nutrino , muon , b) quarks : up , down , top , bottom , charm , strange . Explain all in one thread .

Answer 1

Dear Student,
a) Leptons: Leptons are a class of subatomic particles (also termed as elementary particles) having half integral spin (s = 1/2). THese are the lightest known particles and are hence not involved in strong interactions. There are 6 leptons: Electron, muon, tau, electron neutrino, muon neutrino and tau neutrino. Each particle has its anti particle. Electron, muon, tau have non zero rest mass where as all neutrinos have zero rest mass. Muon and Tau are unstable where as electron and all neutrinos are stable particles.

b) Quarks: Quarks are the elementary particles or basic building blocks of which hadrons (heavy headed particles) are made up of. Hadrons can be classified under two categories: Mesons (integral spin) and Baryons (1/2 integral spin). A quark and an anti-quark pair makes a meson while a combination of three quarks make a baryon. There are 6 "flavours" of Quark: Up, Down, Charm, Strange, Top, Down.

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