Collider Signatures of Flavorful Higgs Bosons

TL;DR

This paper explores collider signatures of a two Higgs doublet model with a non-standard Yukawa sector, highlighting unique production and decay modes involving second-generation fermions, which differ from traditional 2HDMs.

Contribution

It introduces a novel 2HDM framework where the second Higgs doublet gives mass to lighter fermions, leading to distinctive collider signatures and decay modes not seen in standard models.

Findings

New production mechanisms involving second-generation quarks dominate.

Decays such as H/A -> cc, tc, μμ, τμ are significant.

Low mass di-muon resonance searches are effective probes.

Abstract

Motivated by our limited knowledge of the Higgs couplings to first two generation fermions, we analyze the collider phenomenology of a class of two Higgs doublet models (2HDMs) with a non-standard Yukawa sector. One Higgs doublet is mainly responsible for the masses of the weak gauge bosons and the third generation fermions, while the second Higgs doublet provides mass for the lighter fermion generations. The characteristic collider signatures of this setup differ significantly from well-studied 2HDMs with natural flavor conservation, flavor alignment, or minimal flavor violation. New production mechanisms for the heavy scalar, pseudoscalar, and charged Higgs involving second generation quarks can become dominant. The most interesting decay modes include H/A -> cc, tc, {\mu}{\mu}, {\tau}{\mu} and H+ -> cb, cs, {\mu}{\nu}. Searches for low mass di-muon resonances are currently among the best probes of the heavy Higgs bosons in this setup.