The Higgs boson mass constraint and the CP even-CP odd Higgs boson mixing in an MSSM extension

TL;DR

This paper investigates how a vectorlike multiplet affects the mixing of CP even and CP odd Higgs bosons in an MSSM extension, considering the Higgs mass constraint and potential experimental signatures.

Contribution

It computes one-loop contributions to Higgs mixing from a vectorlike multiplet with new CP phases, analyzing their impact on Higgs masses, mixings, and decay branching ratios.

Findings

Vectorlike multiplet contributions can induce significant CP mixing effects.

Higgs decay branching ratios are sensitive to new CP phases.

Potential experimental signatures of Higgs mixing effects are discussed.

Abstract

One loop contributions to the CP even-CP odd Higgs boson mixings arising from contributions due to exchange of a vectorlike multiplet are computed under the Higgs boson mass constraint. The vectorlike multiplet consists of a fourth generation of quarks and a mirror generation. This sector brings in new CP phases which can be large consistent with EDM constraints. In this work we compute the contributions from the exchange of quarks and mirror quarks $t_{4L}, t_{4R}, T_{L}, T_{R}$, and their scalar partners, the squarks and the mirror squarks. The effect of their contributions to the Higgs boson masses and mixings are computed and analyzed. The possibility of measuring the effects of mixing of CP even and CP odd Higgs in experiment is discussed. It is shown that the branching ratios of the Higgs bosons into fermion pairs are sensitive to new physics and specifically to CP phases.