Flavor Changing Neutral Currents in the Lee-Wick Standard Model

TL;DR

This paper investigates the flavor-changing neutral currents in the Lee-Wick Standard Model, showing that such currents are suppressed despite the model not satisfying minimal flavor violation, due to small Yukawa couplings.

Contribution

It provides a detailed analysis of the flavor structure in the Lee-Wick Standard Model, including the effects of integrating out heavy LW-resonances on flavor-changing processes.

Findings

Flavor-changing Z boson couplings are acceptably small due to Yukawa suppression.

New couplings of W bosons to quarks and leptons are induced.

Four-fermion operators from LW-Higgs integration are examined.

Abstract

Recently an extension of the standard model (the Lee-Wick standard model) based on ideas of Lee and Wick (LW) was introduced. It does not contain quadratic divergences in the Higgs mass and hence solves the hierarchy puzzle. The LW-standard model contains new heavy LW-resonances at the TeV scale that decay to ordinary particles. In this paper we examine in more detail the flavor structure of the theory. We integrate out the heavy LW-fermions at tree level and find that this induces flavor changing Z boson couplings. However, these flavor changing neutral currents are acceptably small since they are automatically suppressed by small Yukawa couplings. This is the case even though the theory does not satisfy the principle of minimal flavor violation. New couplings of the charged W bosons to quarks and leptons are also induced. We also integrate out the LW-Higgs and examine the four-fermion operators induced.