Weak currents and Z/sup 0/ production in left-right-symmetric gauge models

The authors present the phenomenology of SU(2)/sub L/*SU(2)/sub R/*U (1)/sub L/*U(1)/sub R/ gauge models of the weak and electromagnetic interactions in a simple parametric form, based on the eigenvectors of the intermediate-vector-boson mass matrix. The neutral-current interactions are described in general by four angles and three Z/sup 0 / masses. For natural extinction of atomic physics parity violation, one Z boson has pure vector couplings, the other two pure axial-vector couplings. Imposing equivalence with the neutrino scattering phenomenology of the Weinberg-Salam model, only one parameter remains; this degree of freedom allows an axial-vector Z boson to have low mass. The observable consequences of a light Z/sup 0/ are explored for e/sup +/e/sup -/ annihilation, Drell-Yan production of lepton pairs, deep-inelastic lepton scattering by neutral currents, and the anomalous magnetic moment of the muon. A Z mass as low as 30 GeV is compatible with existing measurements; the most stringent present limit is set by the muon magnetic moment. The authors estimate a Z/sub 3/(30) signal would be about 10% of the Upsilon (9.5) signal in pp to mu /sup +/ mu /sup -/X at top CERN ISR energies square root s=60 GeV, and that Z/sub 3/(30) would give a -13% asymmetry in e/sup +/e/sup -/ to mu /sup +/ mu /sup -/ at top SPEAR energies square root s=7.5 GeV. (24 refs).