The Higgs field and the associated Higgs boson are not considered a fifth fundamental force because they do not mediate a distinct and separate interaction between particles like the four known fundamental forces: gravity, electromagnetism, the weak nuclear force, and the strong nuclear force. Instead, the Higgs mechanism is responsible for providing mass to particles and is intimately related to the electroweak force.
To understand this further, let's consider the known fundamental forces:
Gravity: Gravity is responsible for the attraction between massive objects and is described by Einstein's theory of general relativity. It acts over long distances and is extremely weak compared to the other forces.
Electromagnetism: Electromagnetism describes the interaction between electrically charged particles and is mediated by photons. It governs phenomena like electric and magnetic forces, electromagnetic radiation, and the behavior of charged particles.
Weak Nuclear Force: The weak nuclear force is responsible for processes such as beta decay and is involved in the interactions between particles that participate in the weak interaction, such as electrons, neutrinos, and quarks. It has a very short range and is mediated by the exchange of W and Z bosons.
Strong Nuclear Force: The strong nuclear force binds quarks together inside protons and neutrons, and it also holds protons and neutrons together in atomic nuclei. It is the strongest force among the four fundamental forces and is mediated by the exchange of gluons.
The Higgs field and the Higgs boson, on the other hand, play a different role. The Higgs field permeates all of space, and when particles interact with this field, they acquire mass. The Higgs field is part of the electroweak theory, which unifies the electromagnetic and weak forces at high energies. The Higgs boson is a manifestation of the excitations of the Higgs field and was discovered in experiments at the Large Hadron Collider (LHC) in 2012.
While the Higgs mechanism is essential for explaining how particles acquire mass, it does not introduce a new fundamental force. It is deeply connected to the electroweak force and is intertwined with the weak nuclear force. So, the Higgs mechanism is considered a fundamental aspect of the electroweak theory, but it does not represent a distinct fifth fundamental force.
It's important to note that the understanding of fundamental forces and particles is based on our current theoretical framework and experimental observations. As our knowledge advances, our understanding of these concepts may evolve, but for now, the Higgs field and the Higgs boson are not regarded as an additional fundamental force.