arXiv subjects
Publications and source records attributed to Morris L. Swartz.
A review of the decade of Z-pole electroweak physics is presented. Although all experimental work has been completed, it represents a ``Golden Age'' in our understanding of the Minimal Electroweak Standard Model (MSM). The latest (and nearly final) results from the LEP and SLC experiments are presented. The remaining inconsistencies are discussed and and their effects upon the MSM interpretation are explored.
We reevaluate the hadronic part of the electromagnetic vacuum expectation value using the standard dispersion integral approach that utilizes the hadronic cross section measured in $\ee$ experiments as input. Previous analyses are based upon point-by-point trapezoidal integration which has the effect of weighting all inputs equally. We use a technique that weights the experimental inputs by their stated uncertainties, includes correlations, and incorporates some refinements. We find the hadronic contribution to the fractional change in the electromagnetic coupling constant at $q^2=M_Z^2$ to be $0.02666\pm0.00075$, which leads to a value of the electromagnetic coupling constant, $α^{-1}(M_Z^2) = 129.08\pm0.10$. This value significantly shifts the Standard Model predictions for the effective weak mixing angle measured at the $Z$ pole and moderately shifts the predicted $Z$ width.