Simple Higgs mechanisms in the SU(2)LU

Abstract

Studies of superstring models suggest that the low-energy gauge group is SU(3)/sub C/ x SU(2)/sub L/ x U(1) x U(1), an extension of the standard model with an additional gauge boson. The fact that there are four massive gauge bosons in the SU(2)/sub L/ x U(1) x U(1) electroweak sector requires introduction of additional Higgs fields in the standard Higgs mechanism, which in turn determines the structure of the ''extended'' electroweak theory. Assuming both that the additional Higgs field be either a singlet or a doublet under SU(2)/sub L/ and that the standard Glashow-Salam-Weinberg theory be reproduced exactly, I derive the resultant SU(2)/sub L/ x U(1) x U(1) electroweak models. A small number of parameter-free solutions for the nonstandard neutral currents are obtained if, as suggested by superstring studies, chiral fermions and Higgs fields are assigned to the 27 representation of the E/sub 6/ gauge group. The unique detailed structure of the extended theory may help in planning to search for manifestations of the nonstandard neutral gauge boson as a test of the superstring idea.