Vector boson
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In particle physics, a vector boson is a boson with the spin equal to 1. The vector bosons regarded as elementary particles in the Standard Model are the gauge bosons, which are the force carriers of fundamental interactions: the photon of electromagnetism, the W and Z bosons of the weak interaction, and the gluons of the strong interaction. Some composite particles are vector bosons, for instance any vector meson (quark and antiquark). During the 1970s and '80s, intermediate vector bosons—vector bosons of "intermediate"[clarification needed] mass—drew much attention in particle physics.[citation needed]
Vector bosons and the Higgs
Certain vector bosons, i.e. the Z and W particles, play a prominent role in the recently announced (July 4, 2012)[1] scalar boson (perhaps the Higgs boson), as shown by the attached Feynman diagram.
(The symbol q means a quark particle, W and Z are the vector bosons of the electroweak interaction. H0 is the Higgs boson.)
Explanation
The name vector boson arises from quantum field theory. The component of such a particle's spin along any axis has the three eigenvalues −ħ, 0, and +ħ (where ħ is the reduced Planck constant), meaning that any measurement of it can only yield one of these values. (This is, at least, true for massive vector bosons; the situation is a bit different for massless particles such as the photon, for reasons beyond the scope of this article. See Wigner's classification.[2]) The space of spin states therefore is a discrete degree of freedom consisting of three states, the same as the number of components of a vector in three-dimensional space. Quantum superpositions of these states can be taken such that they transform under rotations just like the spatial components of a rotating vector[citation needed] (the so named 3 representation of SU(2)). If the vector boson is taken to be the quantum of a field, the field is a vector field, hence the name.
See also
Notes
- ^ "CERN experiments observe particle consistent with long-sought Higgs boson". Press Release by CERN. 2012-07-04. Retrieved 2012-07-12.
- ^ Weingard, Robert. "Some Comments Regarding Spin and Relativity"
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