Constraints on anomalous gauge couplings from present LEP1 and future LEP2, BNL data

Abstract

We analyze, in a rather general model where anomalous triple gauge couplings are present, the visible effects in R b (measured at LEP1), in W pair production (to be measured at LEP2) and in the muon anomalous magnetic moment (to be measured at BNL). From the combination of the three experiments a remarkable improvement on the pure LEP2 constraints is obtained.

Logarithmic expansion of electroweak corrections to four-fermion processes in the TeV region

“…Eqns. (10)(11)(12)(13)(14)(15)(16)(17)(18)(19)(20)(21)(22)(23) are the main results of this paper. They contain in a compact form the leading asymptotic Sudakov-type (double and single log) contributions.…”

“…The simplest example would be provided by a class of models with anomalous triple gauge couplings (AGC)[18]. Here, the effect of the models is that of introducing linear terms of the type q 2 /Λ 2[19], thus changing the energy dependence of the observables as a function of the AGC parameters. Another application could be one that requires integration over a certain fraction of the energy range involving the product of the cross section by known weight functions, like those encountered when computing QED convolution.…”

Status of the Muon (g – 2) Experiment

“…5(a) the triple gauge vertex W W γ appears, and it is through this diagram that the muon (g − 2) obtains its sensitivity to W substructure and anomalous gauge couplings. The combined sensitivity of LEP1, LEP2 and (g − 2), and the unique contribution which (g − 2) makes in constraining the existence of such couplings, is described by Renard et al [30] Supersymmetry has become a serious candidate for physics beyond the standard model. The SUSY contribution is shown in Fig.…”

Bounds on anomalous gauge couplings from past and near future experiments: the role of the different measurements

“…In a previous publication [4], we have analyzed the overall bounds that can be obtained on the "blind" set by a combination of (supposedly negative) experimental results, obtained in the two W channel at LEP2 [5], with those available from the LEP1 measurements of the Z partial width into bb pairs [6] and from the hypothetical future improved measurement of the muon g −2 at BNL [7]. A nice feature of that analysis, in our opinion, was the fact that it pointed out in a clear way the fact that the three different experiments were complementary, each one allowing an improved determination of a different subset of parameters.…”