Indirect constraints on the triple gauge boson couplings from Z -> b(b)over-bar partial width: An update

Abstract

We update the indirect bounds on anomalous triple gauge couplings coming from the non-universal one-loop contributions to the Z --> <b(b)over bar> width. These bounds, which are independent of the Higgs boson mass, are in agreement with the standard model predictions for the gauge boson self-couplings since the present value of R-b agrees fairly well with the theoretical estimates. Moreover, these indirect constraints on Delta g(1)(Z) and g(5)(Z) are most stringent than the present direct bounds on these quantities, while the indirect limit on lambda(Z) is weaker than the available experimental data.