The force that keeps quarks together is known as the strong nuclear force or strong interaction. It is one of the four fundamental forces of nature, along with gravity, electromagnetism, and the weak nuclear force.
The strong force is responsible for binding quarks together to form particles such as protons and neutrons, which are known as hadrons. Quarks are elementary particles that carry fractional electric charges and are considered the building blocks of matter.
The strong force is carried by particles called gluons, which interact with quarks. Unlike other forces, the strength of the strong force does not decrease with distance. In fact, it becomes stronger as quarks move farther apart, making it extremely powerful at short distances. This phenomenon is called asymptotic freedom and is described by a theory known as quantum chromodynamics (QCD).
Within the framework of QCD, the strong force is mediated by the exchange of gluons between quarks. The interaction between quarks and gluons is characterized by a property called color charge, which comes in three types: red, green, and blue. Quarks can have different combinations of color charges, while gluons themselves carry a combination of color and anticolor charges.
The strong force plays a crucial role in the stability of atomic nuclei, as it overcomes the electromagnetic repulsion between positively charged protons. It is also responsible for various phenomena observed in high-energy particle physics experiments, such as the creation and annihilation of quark-antiquark pairs.
Overall, the strong nuclear force is essential for understanding the structure and behavior of matter at the subatomic level and plays a fundamental role in our understanding of particle physics.