The currently accepted theory of particle physics, known as the Standard Model, includes six types of quarks. These quarks are up, down, charm, strange, top, and bottom. Each quark has a different mass and carries a fractional electric charge.
However, it is always possible that our understanding of fundamental particles may evolve as new experimental data and theoretical advancements emerge. The Standard Model is considered to be an effective theory that describes the known elementary particles and their interactions, but it is not considered to be a complete theory of all fundamental particles and forces in the universe.
The possibility of additional quarks or other particles beyond those predicted by the Standard Model is an active area of research in particle physics. Proposed extensions to the Standard Model, such as supersymmetry or theories involving extra dimensions, suggest the existence of additional quarks or exotic particles. However, to date, no direct experimental evidence has confirmed the existence of these hypothetical particles. Ongoing experiments at high-energy particle colliders, such as the Large Hadron Collider (LHC), aim to explore the frontiers of particle physics and may shed light on any potential extensions or modifications to our current understanding of quarks and other fundamental particles.