Implications of CP violating 2HDM in B physics

TL;DR

This paper explores a class of two Higgs doublet models that avoid flavor changing neutral currents at tree level, introduce new CP violating phases in charged Higgs couplings, and can explain recent B meson CP violation hints.

Contribution

It identifies a specific 2HDM class with flavor-dependent CP phases that do not affect K meson CP violation but influence B meson mixing, offering a novel explanation for observed anomalies.

Findings

New CP violating phases in charged Higgs couplings can explain B meson CP violation.

Certain parameter ranges avoid affecting K meson CP violation.

Model predicts identical new physics phases in B_d and B_s mixing.

Abstract

The charged fermion mass matrices are invariant under $U(1)^3$ symmetry linked to the fermion number transformation. Under the condition that the definition of this symmetry in arbitrary weak basis does not depend upon Higgs parameters such as ratio of vacuum expectation values, a class of two Higgs doublet models (2HDM) can be identified in which tree level flavor changing neutral currents normally present in 2HDM are absent. However unlike the type I or type II Higgs doublet models, the charged Higgs couplings in these models contain additional flavor dependent CP violating phases. These phases can account for the recent hints of the beyond standard model CP violation in the $B_d$ and $B_s$ mixing. In particular, there is a range of parameters in which new phases do not contribute to the $K$ meson CP violation but give identical new physics phases in the $B_d$ and $B_s$ meson mixing.