A scalar boson is a boson with spin equal to zero. Some mesons are scalar bosons.

Explanation

The name scalar boson arises from quantum field theory. The component of such a particle's spin along any axis will always be measured to have only one possible value: 0. The space of spin states therefore has one degree of freedom, the same as the number of components of a mathematical scalar. If the scalar boson is taken to be the quantum of a field, the field is a scalar field, hence the name.

Pseudoscalar bosons

Most mesons, such as pion, are pseudoscalar bosons.

See also

• Pseudoscalar meson
• Scalar field theory
• Vector boson