Probing a scalar singlet-catalyzed electroweak phase transition with resonant di-Higgs boson production in the 4b channel
We investigate the prospective reach of the 14 TeV HL-LHC for resonant production of a heavy Higgs boson that decays to two SM-like Higgs bosons in the 4b final state in the scalar singlet extended Standard Model. We focus on the reach for choices of parameters yielding a strong first order electroweak phase transition. The event selection follows the 4b analysis by the ATLAS Collaboration, enhanced with the use of a boosted decision tree method to optimize the discrimination between signal and background events. The output of the multivariate discriminant is used directly in the statistical analysis. The prospective reach of the 4b channel is compatible with previous projections for the bbγγ and 4τ channels for heavy Higgs boson mass m₂ below 500 GeV and superior to these channels for m₂>500 GeV. With 3 ab⁻¹ of integrated luminosity, it is possible to discover the heavy Higgs boson in the 4b channel for m₂<500 GeV in regions of parameter space yielding a strong first order electroweak phase transition and satisfying all other phenomenological constraints
Additional Information© 2019 Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation, and DOI. Funded by SCOAP3. Received 9 August 2019; published 28 October 2019. H. L. and M. J. R. M. were supported in part under U.S. Department of Energy Contract No. DE-SC0011095. H. L. is supported by the National Science Foundation of China under Grants No. 11875003. S. W. is supported in part under U.S. Department of Energy Contract No. DE-SC0010004.
Published - PhysRevD.100.075035.pdf
Submitted - 1906.05289.pdf