Multi-TeV Signals of Baryogenesis in Higgs Troika Model

TL;DR

This paper explores how an extended Higgs model with two extra doublets can explain baryogenesis and predicts signals at future colliders and flavor experiments, linking early Universe physics with high-energy collider phenomenology.

Contribution

It introduces the Higgs Troika Model with Dirac neutrinos, analyzing its collider and flavor signatures relevant for baryogenesis, and highlights the complementarity of future collider and flavor experiments in probing this model.

Findings

Resonant scalar production leads to di-jet or top-pair signals.

Flavor experiments like LHCb can probe key parameter space.

Future 100 TeV collider can detect Higgs states up to 10 TeV.

Abstract

A modest extension of the Standard Model by two additional Higgs doublets - the Higgs Troika Model - can provide a well-motivated scenario for successful baryogenesis if neutrinos are Dirac fermions. Adapting the "Spontaneous Flavor Violation" framework, we consider a version of the Troika model where light quarks have significant couplings to the new multi-TeV Higgs states. Resonant production of new scalars leading to di-jet or top-pair signals are typical predictions of this setup. The initial and final state quarks relevant to the collider phenomenology also play a key role in baryogenesis, potentially providing direct access to the relevant early Universe physics in high energy experiments. Viable baryogenesis generally prefers some hierarchy of masses between the observed and the postulated Higgs states. We show that there is a complementarity between direct searches at a future 100 TeV $pp$ collider and indirect searches at flavor experiments, with both sensitive to different regions of parameter space relevant for baryogenesis. In particular, measurements of $D-\bar{D}$ mixing at LHCb probe much of the interesting parameter space. Direct and indirect searches can uncover the new Higgs states up to masses of $\mathcal{O}(10)$ TeV, thereby providing an impressive reach to investigate this model.