Subatomic Particles

This slideshow is an introduction to the various subatomic particles.

All normal matter is made of 3 subatomic particles - protons, neutrons and electrons. In high-energy collisions in particle accelerators, however, these can be converted into numerous other particles like mesons, pions, kaons etc. It was discovered that many of these particles consist of various combinations of quarks. So a proton consists of two up-quarks and a down-quark and a neutron consists of two down-quarks and an up-quark. Electrons are still fundamental particles, not made of anything else. So, at a more fundamental level, matter is made of up-quarks, down-quarks and electrons.

To complicate things though, it was found that the high-enegy collisions can poduce four other types of quarks and five other types of leptons besides electrons.

These particles are all fermions. There are also bosons - force carrying particles - including gluons, photons, W and Z bosons and the Higgs boson. And . . . there are anti-particles for most of these particles with the same mass but opposite charge. For instance the anti-particle of the electron is the positron. These 30-or-so particles together form 'The Standard Model'.

All but up- and down-quarks, electrons, photons and gluons are very short-lived and not part of ordinary matter.

Dark matter seems not to be made of any of these, so the standard model is not the complete picture.

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