The Impact of Two-Loop Effects on the Scenario of MSSM Higgs Alignment without Decoupling

TL;DR

This paper investigates how two-loop quantum corrections influence the Higgs alignment condition in the MSSM, revealing significant effects that alter previous one-loop based predictions and expanding the understanding of Higgs phenomenology.

Contribution

It provides a detailed analysis of two-loop effects on Higgs alignment in the MSSM, showing their importance and introducing new solutions absent in one-loop approximations.

Findings

Two-loop corrections significantly affect the Higgs alignment condition.

New solutions to the alignment condition emerge at the two-loop level.

Implications for MSSM parameter space and Higgs phenomenology are discussed.

Abstract

In multi-Higgs models, the properties of one neutral scalar state approximate those of the Standard Model (SM) Higgs boson in a limit where the corresponding scalar field is roughly aligned in field space with the scalar doublet vacuum expectation value. In a scenario of alignment without decoupling, a SM-like Higgs boson can be accompanied by additional scalar states whose masses are of a similar order of magnitude. In the Minimal Supersymmetric Standard Model (MSSM), alignment without decoupling can be achieved due to an accidental cancellation of tree-level and radiative loop-level effects. In this paper we assess the impact of the leading two-loop O(alpha_s h_t^2) corrections on the Higgs alignment condition in the MSSM. These corrections are sizable and important in the relevant regions of parameter space and furthermore give rise to solutions of the alignment condition that are not present in the approximate one-loop description. We provide a comprehensive numerical comparison of the alignment condition obtained in the approximate one-loop and two-loop approximations, and discuss its implications for phenomenologically viable regions of the MSSM parameter space.