Effects of Extra Space-time Dimensions on the Fermi Constant

TL;DR

This paper investigates how large extra spatial dimensions influence the Fermi constant and derives constraints on the size and number of such dimensions based on current precision measurements, with implications for future colliders.

Contribution

It provides the first detailed constraints on the size and number of large extra dimensions using precision electroweak data, including the Fermi constant, W and Z masses, and the fine structure constant.

Findings

Excludes one extra dimension below ~1.6 TeV.

Excludes 2, 3, and 4 extra dimensions below ~3.5, 5.7, and 7.8 TeV respectively.

Sets new bounds on the compactification radius of extra dimensions.

Abstract

Effects of Kaluza-Klein excitations associated with extra dimensions with large radius compactifications on the Fermi constant are explored. It is shown that the current precision determinations of the Fermi constant, of the fine structure constant, and of the W and Z mass put stringent constraints on the compactification radius. The analysis excludes one extra space time dimension below $\sim 1.6$ TeV, and excludes 2, 3 and 4 extra space dimensions opening simultaneously below $\sim$ 3.5 TeV, 5.7 TeV and 7.8 TeV at the $90% CL$. Implications of these results for future collider experiments are discussed.