4b + X via electroweak multi-Higgs production as smoking gun signals for Type-I 2HDM at the LHC

¹ Department of Physics, Konkuk University, Seoul 05029, Republic of Korea
² Birla Institute of Technology and Science, Pilani, 333031, Rajasthan, India
³ School of Physics and Astronomy, University of Southampton, Southampton SO17 1BJ, United Kingdom
⁴ Department of Physics and Astronomy, Uppsala University, Box 516, SE-751 20 Uppsala, Sweden
⁵ Department of Physics, Faculty of Natural Sciences and Mathematics, St. Olaf College, Northfield, MN 55057, United States

^* e-mail: prasenjit.sanyal01@gmail.com
^** e-mail: tanmoy.mondal@pilani.bits-pilani.ac.in
^*** e-mail: s.moretti@soton.ac.uk,stefano.moretti@physics.uu.se
^**** e-mail: munir1@stolaf.edu

Published online: 18 December 2024

Abstract

Extending the Standard Model (SM) by one additional Higgs doublet leads to the Two-Higgs Doublet Model (2HDM). A specific charge assignment of the SM fermions under the Z₂ symmetry leads to the Type-I 2HDM. A key feature of the Type-I 2HDM is that all the additional Higgs bosons can be fermiophobic, when their couplings to the SM fermions are suppressed. As a result, all the new Higgs states can be fairly light, ~ 100 GeV or less, without being in conflict with the current data from the direct Higgs boson searches and the B-physics measurements. In a recent study Ref. [1], which this proceeding is based on, we established that the new neutral as well as the charged Higgs bosons in this model can all be simultaneously observable in the multi-b final state at the HL-LHC. An experimental validation of our results would be a clear indication that the true underlying Higgs sector in nature is the Type-I 2HDM. Additionally, in this proceeding we discuss the prospects of our work in the future e⁺e⁻ colliders.