Scheme and scale dependences of leading electroweak corrections Original Research Article

The scheme and scale dependences of leading Mt-dependent contributions to Δg9, Δr and τ, which arise because of the truncation of the perturbative series, are investigated by comparing expressions in the on-shell and MS schemes of renormalization, and studying their scale variations. Starting from the conventional on-shell formulae, we find rather large scheme and scale dependences. We then propose a simple, physically motivated modification of the conventional expressions and show that it leads to a sharp reduction in the scheme and scale dependences. Implications for electroweak physics are discussed.