Higgs Signal for h to aa at Hadron Colliders

TL;DR

This paper evaluates the potential for detecting a Higgs boson decaying into two lighter spin-zero particles at hadron colliders, highlighting the experimental challenges and prospects at the Tevatron and LHC.

Contribution

It introduces the possibility of observing Higgs decays to a pair of light scalars in extended models, emphasizing detection strategies and feasibility at current colliders.

Findings

Potential to observe a few events at the Tevatron with low background.

Feasibility of Higgs detection at the LHC due to higher cross sections and luminosity.

Signal-to-background ratio around 1:2 for the h to aa to bbbb channel.

Abstract

We assess the prospect of observing a neutral Higgs boson at hadron colliders in its decay to two spin-zero states, a, for a Higgs mass of 90-130 GeV, when produced in association with a W or Z boson. Such a decay is allowed in extensions of the MSSM with CP-violating interactions and in the NMSSM, and can dominate Higgs boson final states, thereby evading the LEP constraints on standard Higgs boson production. The light spin-zero state decays primarily via a to bb and tau+tau-, so this signal channel retains features distinct from the main backgrounds. Our study shows that at the Tevatron, there may be potential to observe a few events in the bb tau+tau- or bbbb channels with relatively small background, although this observation would be statistically limited. At the LHC, the background problem is more severe, but with cross sections and integrated luminosities orders of magnitude larger than at the Tevatron, the observation of a Higgs boson in this decay mode would be possible. The channel h to aa to bbbb would provide a large statistical significance, with a signal-to-background ratio on the order of 1:2. In these searches, the main challenge would be to retain the adequate tagging efficiency of b's and tau's in the low p_T region.