Weinberg angle

Weinberg angle θW, and relation between couplings g, g′, and e = g sin θW. Adapted from Lee (1981).[1]
The pattern of weak isospin, T3, and weak hypercharge, YW, of the known elementary particles, showing electric charge, Q,[a] along the Weinberg angle. The neutral Higgs field (upper left, circled) breaks the electroweak symmetry and interacts with other particles to give them mass. Three components of the Higgs field become part of the massive W and Z bosons.

The weak mixing angle or Weinberg angle[2] is a parameter in the Weinberg–Salam theory of the electroweak interaction, part of the Standard Model of particle physics, and is usually denoted as θW. It is the angle by which spontaneous symmetry breaking rotates the original
W0
 and
B0
 vector boson plane, producing as a result the
Z0
 boson, and the photon.[3] Its measured value is slightly below 30°, but also varies, very slightly increasing, depending on how high the relative momentum of the particles involved in the interaction is that the angle is used for.[4]

  1. ^ Lee, T.D. (1981). Particle Physics and Introduction to Field Theory.
  2. ^ Glashow, Sheldon (February 1961). "Partial-symmetries of weak interactions". Nuclear Physics. 22 (4): 579–588. Bibcode:1961NucPh..22..579G. doi:10.1016/0029-5582(61)90469-2.
  3. ^ Cheng, T.P.; Li, L.F. (2006). Gauge Theory of Elementary Particle Physics. Oxford University Press. pp. 349–355. ISBN 0-19-851961-3.
  4. ^ Cite error: The named reference wein was invoked but never defined (see the help page).


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