Searching for Signs of the Second Higgs Doublet

Abstract

The search for evidence of extended electroweak symmetry breaking has entered a new phase with the discovery of a Standard Model (SM)-like Higgs at the LHC. The measurement of Higgs couplings and direct searches for additional scalars provide complementary avenues for the discovery of new degrees of freedom. This complementarity is particularly sharp in two Higgs doublet models (2HDMs) where the couplings of the SM-like Higgs may be directly related to the LHC signals of additional scalars. In this work we develop a strategy for searching for the second Higgs doublet given the LHC signals of the recently discovered SM-like Higgs. We focus on a motivated parameter space of flavor-and CP-conserving 2HDMs in which the couplings of all scalars to SM states are controlled by two parameters. We construct fits in this parameter space to the signals of the SM-like Higgs and translate these fits into signal expectations for future measurements of both the SM-like Higgs and additional scalars, identifying the most promising search channels for discovery or exclusion of new physics. When kinematically accessible, decays of the heavy neutral scalar Higgs to two light Higgs scalars, H → hh, and decays of the pseudoscalar Higgs to a light Higgs scalar and Z boson, A → Zh, provide promising avenues for discovery even when the couplings of the light Higgs are within a few percent of SM predictions. When the couplings of the light Higgs are exceptionally close to those of the SM, decays of heavier neutral scalars to γγ and τ + τ − become particularly important for discovery.

Doubling down on naturalness with a supersymmetric twin Higgs

“…Where two-sided measurements are unavailable, we use an approximate gaussian likelihood constructed from the observed and expected limits. 6 To determine the dependence of the signal strength on the relevant SUSY twin Higgs parameters f, m A , and tan β, we use the techniques of [34] with the tree-level coupling modifiers in Eq. 21 plus the invisible width in Eq.…”

Role of supersymmetric heavy Higgs boson production in the self-coupling measurement of 125 GeV Higgs boson at the LHC

“…• In this paper we only consider heavy Higgs to hh decay. Depending on the parameter space, several potentially observable decay modes [50,51] may open and in principle, MSSM Higgs bosons can be discovered in other channels. A detailed study is beyond the scope of this paper and these issues will be considered in a separate work [49].…”

Entropy production due to electroweak phase transition in the framework of two Higgs doublet model

“…The impact of the cos(β − α) − tan β plane has been discussed in ref. [35]. A hierarchical spectrum like m A > m H ∼ m H ± ∼ v can lead to a first order EWPT providing an explanation for the matter-antimatter asymmetry.…”