Relating the Cabibbo angle to tanβ in a two Higgs-doublet model

Dipankar Das

doi:10.1103/physrevd.100.075004

Abstract

In a two Higgs-doublet model with $D_4$ flavor symmetry, we establish a relation between $\tan\beta$ and the Cabibbo angle. Due to a small number of parameters, the quark Yukawa sector of the model is very predictive. The flavor changing neutral currents are small enough to allow for relatively light nonstandard scalars to pass through the flavor constraints.

Highlights

Employing flavor symmetries to understand the apparent arbitrariness of the quark masses and mixings in the Standard Model (SM) is an exercise continuing for decades
A flavor-model that contains five or fewer parameters in its quark Yukawa Lagrangian, might have a better aesthetic appeal than the SM in the sense that many of the redundant parameters have been erased by the flavor symmetry leaving behind only the relevant ones
These objectives can be achieved in the simple framework of a two Higgs-doublet model (2HDM) [1,2] with a D4 flavor symmetry

Summary

Dipankar Das*

Theoretical constructions beyond the SM (BSM) that attempt to address these issues in a minimalistic manner should deserve some attention To this end, we notice that the quark masses and mixings adhere to the following approximate pattern, mu. The quantity sin θC ≈ 0.22 appearing in Eq (1) denote the Cabibbo mixing parameter In this approximate scenario, we note that there are only five nonzero parameters in the quark sector, namely, four quark masses (mc; ms; mt; mb) and the Cabibbo parameter itself. A flavor-model that contains five or fewer parameters in its quark Yukawa Lagrangian, might have a better aesthetic appeal than the SM in the sense that many of the redundant parameters have been erased by the flavor symmetry leaving behind only the relevant ones.

DIPANKAR DAS

One can easily check that

LCYP even h v ðu Duu þ d DddÞ