# Predicting Alignment in a Two Higgs Doublet Model

## TL;DR

This paper demonstrates that a non-abelian $SU(2)_R$ symmetry in the two Higgs doublet model naturally leads to alignment at tree level, with minimal radiative correction, relevant for supersymmetric theories.

## Contribution

It introduces a novel symmetry-based mechanism for alignment in 2HDMs, connecting it to $SU(2)_R$ and supersymmetry, and discusses its phenomenological implications.

## Key findings

- Tree-level alignment achieved via $SU(2)_R$ symmetry.
- Minimal radiative misalignment in the model.
- Connection between $SU(2)_R$ and $N=2$ supersymmetry.

## Abstract

We show that a non-abelian global $SU(2)_R$ acting on the quartic part of the two Higgs Doublet Model leads, at tree-level, to an automatic alignment without decoupling. An example of phenomenologically viable model with this feature is the the low energy effective field theory of the Minimal Dirac Gaugino Supersymmetric Model in the limit where the adjoint scalars are decoupled. We discuss here how the $SU(2)_R$ can be identified with the R-symmetry of the $N=2$ supersymmetry in the gauge and Higgs sectors. We also review how the radiative corrections lead to a very small misalignment.