Explaining Dijet Mass Excesses in ALEPH LEP2 Four-Jet Events with 2HDMs

TL;DR

This paper explores how light Higgs bosons in 2HDMs could explain the observed dijet mass excesses in ALEPH LEP2 four-jet events, proposing specific mass points that produce observable signals.

Contribution

It demonstrates that certain parameter points in Type-I and -III 2HDMs can account for the ALEPH four-jet excesses with light Higgs bosons, providing a potential new physics explanation.

Findings

Identified parameter regions in 2HDMs compatible with ALEPH excesses.

Showed that light Higgs states can produce observable four-jet signatures.

Suggested specific Higgs mass configurations that fit the data.

Abstract

In this paper, we address the observability of four-jet signatures from light neutral and charged Higgs bosons at LEP2 energies in the framework of 2-Higgs Doublet Models (2HDMs). The main signal production channels are via $e^+ e^- \to Ah$ and $H^+ H^-$ with subsequent quark decays of such final states into four-jets. Specifically, Type-I and -III realizations of a generic 2HDM (2HDM-I and -III, respectively) are adopted to show that there exist points (under the assumption that the heavy Higgs state $H$ is SM-like) for which $(m_h, m_A, m_{H^\pm}) \approx (80, 30, 55)$ GeV that can yield observable rates at LEP2 energies that can potentially explain the di-jet mass excesses seen recently in ALEPH data in a re-analysis of their four-jet samples, particularly so for the 2HDM-III.