SU(2) x U(1) vectorlike model: New leptons, quarks, and the axion question
We present a detailed study of an SU(2) x U(1) gauge theory of the weak and electromagnetic interactions in which parity is broken spontaneously. A global, chiral U(1) symmetry is incorporated in order to avoid a zeroth-order neutrino mass. We investigate an eight-quark scheme and two different lepton assignments, each of which produces almost pure vector coupling of the electron to the weak neutral current. One lepton assignment leads to a calculable neutrino mass, while the other one leads to calculable electron and neutrino masses. There are heavy leptons in the models whose masses are mildly constrained by the bound on the electron-neutrino mass. The neutrino-mass limit and the interpretation of the UPSILON as a bound state of a heavy right-handed quark require that the expectation value of a ''left'' Higgs doublet be small compared to that of a ''right'' Higgs doublet. Because of the global U(1) symmetry, if one or more extra Higgs particles and/or quark singlets are added then an axion can be present. The conditions under which an axion appears are sketched, and its couplings and mass are less restricted than those discussed by other authors. Alternatively, a soft breaking of the U(1) symmetry can be introduced to avoid a Goldstone boson and to insure that both Higgs doublets have nonzero vacuum expectation values. Suppression of strong CP violation can be naturally achieved in this case, and the axion is not present. Both the axion and the soft-breaking possibilities are discussed.
- Research Organization:
- Department of Physics and Astronomy, University of Kansas, Lawrence, Kansas 66045
- OSTI ID:
- 6266776
- Journal Information:
- Phys. Rev., D; (United States), Vol. 19:3
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
UNIFIED GAUGE MODELS
SU-2 GROUPS
U-1 GROUPS
AXIONS
BOUND STATE
CHIRAL SYMMETRY
GOLDSTONE BOSONS
HIGGS MODEL
LEPTONS
P INVARIANCE
QUANTUM CHROMODYNAMICS
QUARK MODEL
SYMMETRY BREAKING
VACUUM STATES
WEAK NEUTRAL CURRENTS
ALGEBRAIC CURRENTS
BOSONS
COMPOSITE MODELS
CURRENTS
ELEMENTARY PARTICLES
FERMIONS
FIELD THEORIES
INVARIANCE PRINCIPLES
LIE GROUPS
MATHEMATICAL MODELS
NEUTRAL CURRENTS
PARTICLE MODELS
POSTULATED PARTICLES
QUANTUM FIELD THEORY
SU GROUPS
SYMMETRY
SYMMETRY GROUPS
U GROUPS
645202* - High Energy Physics- Particle Interactions & Properties-Theoretical- Electromagnetic Interactions & Properties
645203 - High Energy Physics- Particle Interactions & Properties-Theoretical- Weak Interactions & Properties
645400 - High Energy Physics- Field Theory