Particle introduction

1) Electron

Theorized Richard Laming (1838–1851),G. Johnstone Stoney (1874) and others.

Discovered J. J. Thomson (1897)

1 a ) Positron (also called anti electron)

Paul Dirac (1928)

Discovered Carl D. Anderson (1932)

2) Neutron

Theorized Ernest Rutherford (1920)

Discovered James Chadwick  (1932)

2 a) Antineutron

Discovered Bruce Cork (1956)

3) Proton

Theorized William Prout (1815)

Discovered Ernest Rutherford (1917-1919)

3 a) Antiproton

Predicted by Paul Dirac

Discovered physicists Emilio Segrè and

Owen Chamberlain.

Particle introduction

 1 Elementary particle

1.1 Fermions

1.1.1 Quarks

1.1.2 Leptons

1.2 Bosons

1.3 Hypothetical particles

2 Composite particles

2.1 Hadrons

2.1.1 Baryons (fermions)

2.1.2 Mesons (bosons)

Fermion (named after Enrico Fermi)  is any particle which obeys the Fermi–Dirac statistics (and follows the Pauli exclusion principle). Fermions contrast with bosons which obey Bose–Einstein statistics.

A quark is an elementary particle and a fundamental constituent of matter. Quarks combine to form composite particles called hadrons, the most stable of which are protons and neutrons.

A lepton is an elementary particle and a fundamental constituent of matter.^[1] The best known of all leptons is the electron which governs nearly all of chemistry as it is found in atoms and is directly tied to all chemical properties.

bosons are one of the two fundamental classes of subatomic particles, the other being fermions. Bosons are characterized by their obedience to Bose–Einstein statistics. This class of particles includes photons and gluons, as well as the hypothetical Higgs boson.

A hadron is a composite particle made of quarks held together by the strong force (as atoms and molecules are held together by the electromagnetic force). Hadrons are categorized into two families: baryons (made of three quarks) and mesons (made of one quark and one anti quark).

A baryon is a composite subatomic particle made up of three quarks (as distinct from mesons, which comprise one quark and one antiquark). Baryons and mesons belong to the hadron family, which are the quark-based particles. The name "baryon" comes from the Greek word for "heavy" ,because, at the time of their naming, most known elementary particles had lower masses than the baryons.

Mesons are unstable subatomic particles composed of one quark and one anti quark. They are part of the hadron particle family – particles made of quarks. The other members of the hadron family are the baryons – subatomic particles composed of three quarks. The main difference between mesons and baryons is that mesons have integer spin (thus are bosons) while baryons are fermions (half-integer spin). Because mesons are bosons, the Pauli Exclusion Principle does not apply to them. Because of this, they can act as force mediating particles on short distances, and thus play a part in processes such as the nuclear interaction.