Precision Electroweak Constraints on the N=3 Lee-Wick Standard Model

TL;DR

This paper investigates how N=3 Lee-Wick Standard Model extensions influence precision electroweak measurements, finding they can be consistent with current constraints and potentially detectable at the LHC.

Contribution

It extends the Lee-Wick Standard Model to include N=3 states and analyzes their impact on electroweak precision observables, showing viability for collider searches.

Findings

N=3 LW partners have marginal effects on some observables.

Higgs partners can improve Zbb coupling predictions.

LW models remain compatible with current experimental constraints.

Abstract

The Lee-Wick (LW) formulation of higher-derivative theories can be extended from one in which the extra degrees of freedom are represented as a single heavy, negative-norm partner for each known particle (N=2), to one in which a second, positive-norm partner appears (N=3). We explore the extent to which the presence of these additional states in a LW Standard Model affect precision electroweak observables, and find that they tend either to have a marginal effect (e.g., quark partners on T), or a substantial beneficial effect (e.g., Higgs partners on the Zbb couplings). We find that precision constraints allow LW partners to exist in broad regions of mass parameter space accessible at the LHC, making LW theories a viable beyond-Standard Model candidate.