The standard model (or standard model of particle physics) is a current well-accepted working model of particles which describes a structure to nucleons (protons and neutrons) as composite particles made up of smaller elementary particles called quarks, and includes a boson involved in the strong force called a gluon. It outlines a pattern among the known particles, giving order to the growing set of known particle types. It is consistent with electroweak and the strong force, but it does not explain all aspects of particle interactions, thus is considered merely a step toward a more complete model. It grew from ideas developed in the 1960s, gained serious acceptance in the 1970s and has been tweaked and expanded ever since, and proposed theories to cover more detail regarding particle interactions (e.g., supersymmetry) invariably build on it. The model's elementary particle types:
|leptons:||electron neutrino||muon neutrino||tau neutrino||bosons:||W|
The meaning of standard model depends upon context. It is often used without qualification in particle physics, and in other disciplines for their own standard models, i.e., their presumably-best-accepted models, usable as working models, and whose details are well known and well documented. An example is Lambda-CDM model in the field of cosmology.