What is su 4?

SU(4) denotes the special unitary group of degree 4. It is a Lie group, which is a mathematical concept used to study continuous symmetry. The group consists of all 4x4 complex matrices that preserve the complex inner product on a 4-dimensional vector space.

In physics, SU(4) has applications in the study of the strong nuclear force, which binds together quarks to form protons and neutrons. Specifically, SU(4) symmetry is used to describe the behavior of hadrons composed of four quarks, known as tetraquarks. It is also used to describe the properties of mesons composed of two quarks and two antiquarks.

SU(4) has a number of interesting properties, including being a simple Lie group, meaning it cannot be decomposed into simpler groups, and being a compact group, meaning its elements can be transformed continuously into each other without leaving the group. It also has important connections to other areas of mathematics and physics, including algebraic geometry, representation theory, and string theory.