Signatures of Extra Dimensions from Upsilon Decays with a Light Gaugephobic Higgs Boson

TL;DR

This paper investigates the potential to detect a light, gaugephobic Higgs boson through Upsilon decays, proposing that B-factories could discover such a Higgs if it escapes detection at the LHC, thus exploring non-standard Higgs phenomenology in extra-dimensional models.

Contribution

It introduces a model where a light Higgs with suppressed couplings can evade current bounds and proposes Upsilon decay channels as a discovery mode for future experiments.

Findings

Upsilon decays can reveal a light Higgs with suppressed couplings.

B-factories like BaBar, Belle, and CLEO can probe the Higgs parameter space.

Super-B factories could further explore this Higgs if not found at the LHC.

Abstract

We explore non-standard Higgs phenomenology in the Gaugephobic Higgs model in which the Higgs can be lighter than the usually quoted current experimental bound. The Higgs propagates in the bulk of a 5D space-time and Electroweak Symmetry Breaking occurs by a combination of boundary conditions in the extra dimension and an elementary Higgs. The Higgs can thus have a significantly suppressed coupling to the other Standard Model fields. A large enough suppression can be found to escape all limits and allow for a Higgs of any mass, which would be associated with the discovery of W' and Z' Kaluza-Klein resonances at the LHC. The Higgs can be precisely discovered at B-factories while the LHC would be insensitive to it due to high backgrounds. In this letter we study the Higgs discovery mode in Upsilon(3S), Upsilon(2S), and Upsilon(1S) decays, and the model parameter space that will be probed by BaBar, Belle, and CLEO data. In the absence of an early discovery of a heavy Higgs at the LHC, A Super-B factory would be an excellent option to further probe this region.