The W and Z bosons are fundamental particles that mediate the weak nuclear force in particle physics.

The weak nuclear force is one of the four fundamental forces of nature, alongside gravity, electromagnetism, and the strong nuclear force. It plays a critical role in processes such as particle decay and the fusion of hydrogen in stars. The W and Z bosons serve as the force carriers for the weak nuclear force, enabling particles to interact via this interaction.

There are two types of W bosons: $W^+$ and $W^-$. These bosons are responsible for the decay processes of various particles, including the neutron and the muon. In contrast, the Z boson is associated with neutral current interactions, where a particle remains unchanged after interacting with another particle through the weak nuclear force.

The discovery of the W and Z bosons marked a significant milestone in particle physics, as it provided compelling evidence for the existence of the weak nuclear force and demonstrated the unification of the electromagnetic and weak interactions. This breakthrough also facilitated the development of the electroweak theory, which describes how these two forces are interconnected.

In summary, the W and Z bosons are essential components of particle physics, mediating the weak nuclear force that governs particle decay and fusion. Their discovery has significantly advanced our understanding of the fundamental forces of nature and has paved the way for the formulation of the electroweak theory.