Quarks

Quarks are the fundamental subatomic particles that make up all hadrons.

Types are:

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

They have fractional electric charges and baryon numbers:

Antiquarks

Antiquarks are the antiparticles to quarks with opposite baryon number, charge and strangeness.

Hadron quark compositions

The difference between Baryons and Mesons is the number of quarks that they contain. Baryons contain combinations of 3 quarks or 3 antiquarks.

Example: Proton

The proton contains 2 up quarks and 1 down quark.

Example: Neutron

The neutron contains 1 up quark and 2 down quarks.

Mesons:

Mesons contain one quark and one antiquark. They have a baryon number of 0.

Example: ${\pi }^{+}$

The ${\pi }^{+}$ meson is comprised of 1 up quark and 1 anti-down quark

Discoveries in particle physics

Predicting existence of quarks and other particles relies on collaborative analysis from large teams (e.g. at CERN).

Confirming predictions cements acceptance of theories like quarks making up all hadrons.

So quarks form the basis for all composite particles feeling the strong interaction. Their properties explain how hadrons gain their mass, charge and stability.