Exotic Higgs decays at a muon collider

Authors:
Open Access
Publisher website
Google Scholar
Abstract
We study the sensitivity of a future muon collider to exotic Higgs decays in a minimal scenario of Standard Model (SM) augmented with a light singlet scalar S . We consider the decay h → S S and S ’s subsequently decay back to SM. In particular, we focus on final states with four bottom quarks ( 4 b ), and two bottom quarks and two muons ( 2 b 2 μ ). Analyses are performed for two muon collider benchmark configurations: center-of-mass collision energy s = 3 TeV with 1 ab − 1 data and s = 10 TeV with 10 ab − 1 data. Machine-learning techniques are applied to suppress backgrounds and mitigate jet-combinatorics effects in both channels. We find that the 4 b mode could be sensitive to the branching ratio, BR ( h → S S → 4 b ) , of O ( 10 − 2 ) at 3 TeV and O ( 10 − 3 ) at 10 TeV, significantly improving upon high-luminosity LHC projections. In the Higgs-portal model with S coupling to SM only through mixing with the Higgs, the sensitivities to BR ( h → S S ) remain at the same level given O ( 1 ) branching fraction of S decaying into b -quarks. The 2 b 2 μ mode benefits from a clean dimuon resonance and can probe BR ( h → S S → 2 b 2 μ ) down to 10 − 5 level at a 10 TeV muon collider. But the sensitivity to BR ( h → S S ) will be significantly reduced due to the small branching fraction of S decaying into muons in the Higgs portal model.
All Related Versions
Funding Information
  • U.S. Department of Energy (DE-SC-0010010)
  • Research Grants Council, University Grants Committee
  • General Research Fund (16305425)

This publication has 98 references indexed in Scilit: