Decadal Mission for the New Physics Higgs/Flavor Era

TL;DR

This paper proposes that an extra Higgs doublet with specific couplings could explain electroweak baryogenesis, evade current detection, and open a new era in Higgs and flavor physics, suggesting new particles at sub-TeV to 20 TeV scales.

Contribution

It introduces a model with an extra Higgs doublet carrying Weinberg couplings, highlighting its potential for electroweak baryogenesis and guiding future collider searches.

Findings

Extra Higgs bosons can induce a first order electroweak phase transition.

Large Weinberg couplings like ρ_tt and ρ_tc can drive baryogenesis.

Predicted signals at the LHC include specific top and bottom quark processes.

Abstract

The LHC has not discovered any New Physics beyond the anticipated $h(125)$ boson, and new ideas abound for out-of-the-box searches, or Effective Field Theories with multi-TeV cutoff. But, have we exhausted dimension-4 operators involving sub-TeV particles that are {\it not} exotic (non-XLP)? We advocate the existence of an extra Higgs doublet that carry extra Weinberg couplings, where {\it emergent} mass-mixing hierarchies {\it and} alignment have hidden their effects very well so far. ${\cal O}(1)$ Higgs quartics can induce first order electroweak phase transition and imply sub-TeV $H, A, H^\pm$ spectrum. The extra Weinberg couplings, led by $\rho_{tt}$ and $\rho_{tc}$ at ${\cal O}(1)$, can drive electroweak baryogenesis, while $|\rho_{ee}/\rho_{tt}| \propto \lambda_e/\lambda_t$, the ratio of usual electron and top Weinberg couplings, can tame electron EDM. Finding these extra Higgs bosons via $cg \to tH/A \to tt\bar c$, $tt\bar t$ and $cg \to bH^+ \to bt\bar b$ processes (and those allowed by Higgs boson splittings) at the LHC, and pushing the flavor frontier to break the flavor code, would usher in a new Higgs/flavor era. A new scale at 10--20 TeV, possibly related to the Landau pole of the scalar sector, may emerge.