One-Loop Threshold Effects in String Unification

Abstract

Like grand unification of old, string unification predicts simple tree-level relations between the couplings of all unbroken gauge groups such as $SU(3{)}_C$ or $SU(2)_W\)$. I show here how to compute one-loop corrections to these relations for any four-dimensional model based on a classical vacuum of the heterotic string. The result can be used to calculate both ${\sin }^2{\theta }_W$ and ${\Lambda }_{\mathrm{QCD}}$ in terms of ${\alpha }_{\mathrm{QED}}$ and $\mpl\)$. The original version of this paper was written in 1987 and published in Nuclear Physics in 1988. That version had a few factor-of-two errors, which lead some people into confusion. To avoid future confusion, I've written Errata; they are submitted separately to hep-th (article #9205068). This submission is the complete revised version of the paper.

revised version. 17 pages, no figures. Uses phyzzx macropackage

Cited by in corpus (4)

• Thresholds for Intersecting D-branes Revisited
• Compact Dimensions and their Radiative Mixing
• The computation of one-loop heterotic string threshold corrections for general orbifold models with discrete Wilson lines
• Issues on tadpoles and vacuum redefinitions in String Theory