Next generation Higgs bosons: Theory, constraints, and discovery prospects at the Large Hadron Collider

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 to standard model fermions are allowed. 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 $b\ensuremath{\rightarrow}s\ensuremath{\gamma}$ decays, and LEP2 direct production limits. We investigate the energy range of the 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 $Ah\ensuremath{\rightarrow}hhZ\ensuremath{\rightarrow}4b+2l$ signal events, and describe the capability of discovery at the Large Hadron Collider.