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At present, we understand that there are two categories of fundamental particles: bosons and fermions.

Contents 1 Elementary Particles 1.1 Fermions 1.1.1 Quarks 1.1.2 Leptons 1.2 Bosons 2 Composite Particles 2.1 Hadrons 2.2 Baryons 2.3 Mesons

[edit] Elementary Particles

[edit] Fermions

Fermions are things that we normally associate with matter. Examples of fermions are quarks, which combine to make up protons and neutrons, and electrons. There are other more exotics particles that are fermions.

[edit] Quarks

Quarks are the basis of most elements in the present world, at the present day there are 6 known (non-anti-) quarks, these are:

• Up
• Down
• Strange
• Charm
• Bottom
• Top

Each of these have their own respective anti-quark; this adds up to a total of 12 quarks.

[edit] Leptons

Leptons do not experience strong interaction such are that of a nuclear force. The leptons form a family of elementary particles that are distinct from the other known family of fermions: the quarks. There are 6 different Leptons in total, consisting of:

• Electron
• Muon
• Tau lepton
• Electron Neutrino
• Muon neutrino
• Tau neutrino

The leptons have Anti-Leptons just like that of the Quarks although their names are different, the Anti-Leptons consist of;

• Positron
• Muon (no change)
• Tau Lepton (no change)
• Electron antineutrino
• Muon antineutrino
• Tau antineutrino

[edit] Bosons

Bosons are particles that mediate forces, such as light and gravity. Light is mediated by photons and gravity by gravitons. All Bosons have an integer spin, unlike Fermions. The Higg's Boson is a theoretical particle that has yet to be discovered. Scientists hope the Higg's Boson explain why some particles are heavy and others, like the photon, are massless.

[edit] Composite Particles

[edit] Hadrons

Hadrons are strongly interacting composite subatomic particles. They are classified into two seperate classes, which are:

• Baryons
• Mesons

Both of these consist of of quarks.

[edit] Baryons

Baryons are strongly interacting Fermions, such as a Proton or a Neutron, both of which are made up 3 Quarks. Baryons have a Baryon No. of 1. The list of Baryons consist of:

• Proton
• Neutron
• Delta
• Lambda
• Sigma
• Xi
• Omega

[edit] Mesons

Mesons are strongly interacting Bosons which consist of a Quark and an Anti-Quark. Mesons have a Baryon No. of 0. N.B. Mesons cannot have a Quark and its own Anti-Quark, as this is a process called Particle-antiparticle annihilation. There are two basic Mesons:

• Pion
• Kaon