The Standard Model of particle physics is a theoretical framework that describes the fundamental particles and their interactions. It is considered the most successful and widely accepted theory in particle physics to date. The Standard Model incorporates three of the four fundamental forces of nature: electromagnetism, the weak nuclear force, and the strong nuclear force. However, it does not include gravity, which is described by the theory of general relativity.
The Standard Model consists of two main types of particles: fermions and bosons. Fermions are the building blocks of matter and include quarks and leptons. Quarks are elementary particles that combine to form protons and neutrons, which in turn make up atomic nuclei. Leptons include particles like electrons and neutrinos.
Bosons are force-carrying particles, which mediate the interactions between fermions. The photon is the mediator of electromagnetism, the W and Z bosons mediate the weak nuclear force, and gluons mediate the strong nuclear force. The Higgs boson, discovered in 2012, is also part of the Standard Model and is responsible for giving other particles mass.
The Standard Model successfully explains a wide range of phenomena and has been validated by numerous experimental observations. However, it does have some limitations. For example, it does not account for gravity, and it does not provide an explanation for dark matter or dark energy, which are believed to make up a significant portion of the universe. Scientists continue to search for extensions to the Standard Model that can address these and other unanswered questions in physics.