On the flavor structure of the littlest Higgs model

TL;DR

This paper analyzes the flavor structure of the Littlest Higgs model, deriving quark mass and mixing formulas, and predicting flavor-changing neutral currents and rare decays relevant for collider experiments.

Contribution

It provides a detailed analysis of the Yukawa sector, including corrections to CKM matrix elements and FCNC couplings, in the Littlest Higgs model.

Findings

Derived general quark mass and mixing formulas.

Predicted FCNC couplings for up-like quark transitions.

Made predictions for D0-D0bar mixing and rare decay rates.

Abstract

We investigate the Yukawa sector for up-like quarks in the Lee's version of the Littlest Higgs model. We derive general quark mass and mixing formulae and study leading order contributions due to non-zero light quark masses. Relying on the unitarity of the generalized quark mixing matrix we obtain corrections to the CKM matrix elements. In this model FCNCs appear at the tree level and using leading order contributions we obtain the FCNC couplings for the up-like quark transitions. In light of recent experimental results on the D0 - D0bar transition we make predictions for xD as well as the D to mu+ mu- decay rate. Finally, we discuss probabilities for the t to c (u) Z transitions relevant for the LHC studies.