Constraints on split-UED from Electroweak Precision Tests

TL;DR

This paper improves electroweak precision constraints on the split-UED model by analyzing muon decay contributions from W-boson Kaluza-Klein modes, providing bounds relevant for LHC tests.

Contribution

It introduces the first detailed analysis of even-numbered W-boson KK mode effects on muon decay in split-UED models, refining parameter space constraints.

Findings

Stronger bounds on split-UED parameters from electroweak data

Dominant contribution from even W-boson KK modes to muon decay

Predicted mass differences testable at the LHC

Abstract

We present strongly improved electroweak precision constraints on the split-UED model. We find that the dominating effect arises from contributions to the muon decay rate by the exchange of even-numbered W-boson Kaluza-Klein modes at tree-level, which so far have not been discussed in the context of UED models. The constraints on the split-UED parameter space are translated into bounds on the mass difference of the first Kaluza-Klein mode of fermions and the lightest Kaluza-Klein mode, which will be tested is the LHC.