Discovering Nonstandard Higgs bosons in the H -> ZA Channel Decay to Multileptons

TL;DR

This paper explores the potential to detect nonstandard Higgs bosons decaying into Z and tau pairs at the LHC, proposing new analysis strategies and projecting future experimental sensitivities within the NMSSM framework.

Contribution

It introduces three NMSSM benchmark scenarios with dominant H -> ZA decays and evaluates the current and future LHC sensitivity to these signals using multilepton analyses.

Findings

Current CMS data constrains leptophilic NMSSM scenarios.

Future LHC data could nearly exclude the benchmark scenarios.

Boosted di-tau jets could improve detection efficiency.

Abstract

In this article we consider the possibility of observing nonstandard Higgs bosons in the H -> Z A -> Z tau+ tau- channel. We present three benchmark scenarios in the NMSSM where H -> ZA is the dominant decay mode for one of the nonstandard Higgs bosons while the lightest CP-even Higgs is Standard Model like. Using the latest CMS multilepton analysis based on 7 TeV LHC data, we put limits on the signal cross-section, which constrain leptophilic scenarios. Projecting to future LHC analyses with improvements in background modeling, we show that with O(30) fb^{-1} of data, such a multilepton analysis is very close to constraining our NMSSM benchmarks. As we illustrate with a toy model, for light A masses, the large boost of the A makes it inefficient to select two hadronic taus, since isolation and the transverse momenta are in tension. This efficiency could be improved by including boosted di-tau jets as an object in future multilepton analyses. We also discuss different methods to confirm this scenario by reconstruction of the m_H and m_A masses. In particular we consider the transverse mass distribution, collinear mass distribution and an analytical solution using trial masses.