Next Generation Higgs Bosons: Theory, Constraints and Discovery Prospects at the Large Hadron Collider

TL;DR

This paper explores theoretical models of additional Higgs bosons inspired by string theory, examines experimental constraints, and evaluates prospects for discovering these particles at the Large Hadron Collider.

Contribution

It provides a comprehensive analysis of next generation Higgs bosons, including their potential, constraints, and collider signatures, within both Standard Model and supersymmetric frameworks.

Findings

Constraints from meson mixing and $b\to s\gamma$ decays limit parameter space.

Certain models marginally improve the Higgs mass fine-tuning problem.

Potential collider signals like $Ah\to hhZ\to 4b+2l$ could be detectable at the LHC.

Abstract

Particle physics model building within the context of string theory suggests that further copies of the Higgs boson sector may be expected. Concerns regarding tree-level flavor changing neutral currents are easiest to allay if little or no couplings of next generation Higgs bosons are allowed to Standard Model fermions. We detail the resulting general Higgs potential and mass spectroscopy in both a Standard Model extension and a supersymmetric extension. We present the important experimental constraints from meson-meson mixing, loop-induced $b\to s\gamma$ decays and LEP2 direct production limits. We investigate the energy range of valid perturbation theory of these ideas. In the supersymmetric context we present a class of examples that marginally aids the fine-tuning problem for parameter space where the lightest Higgs boson mass is greater than the Standard Model limit of 114 GeV. Finally, we study collider physics signatures generic to next generation Higgs bosons, with special emphasis on $Ah\to hhZ\to 4b+2l$ signal events, and describe the capability of discovery at the Large Hadron Collider.