Renormalization of mixing angles

TL;DR

This paper reviews and introduces new renormalization schemes for mixing angles in extended scalar theories, demonstrating their effectiveness through electroweak correction calculations in specific Higgs models.

Contribution

It proposes novel on-shell and symmetry-based renormalization schemes for mixing angles, improving upon existing methods in extended scalar sector theories.

Findings

New renormalization schemes are well-behaved in benchmark scenarios.

Electroweak corrections are computed for Higgs decay and production processes.

Comparison shows advantages of proposed schemes over traditional ones.

Abstract

We discuss the renormalization of mixing angles for theories with extended scalar sectors. Motivated by shortcomings of existing schemes for mixing angles, we review existing renormalization schemes and introduce new ones based on on-shell conditions or symmetry requirements such as rigid or background-field gauge invariance. Considering in particular the renormalization of the mixing angles in the Two-Higgs-Doublet Model and the Higgs-Singlet Extension of the Standard Model, we compare electroweak corrections within these models for a selection of renormalization schemes. As specific examples, we present next-to-leading-order results on the four-fermion decays of heavy and light CP-even Higgs bosons, $H_1/H_2\to WW/Z Z\to4f$, and on electroweak Higgs-boson production processes, i.e. Higgs-strahlung and vector-boson fusion. We find that our new proposals for on-shell and symmetry-based renormalization conditions are well-behaved for the considered benchmark scenarios in both models.