https://doi.org/10.1140/epjc/s10052-024-13274-8
Regular Article - Theoretical Physics
Searching for exotic Higgs bosons from top quark decays at the HL-LHC
1
Saha Institute of Nuclear Physics, 1/AF Bidhan Nagar, 700064, Kolkata, India
2
Homi Bhabha National Institute, Training School Complex, Anushaktinagar, 400094, Mumbai, India
3
Universite’ de Strasbourg, CNRS, IPHC UMR 7178, Strasbourg, France
4
Department of Physics and Material Science and Engineering, Jaypee Institute of Information Technology, A-10, Sector-62, 201307, Noida, Uttar Pradesh, India
5
School of Physical Sciences, Indian Association for the Cultivation of Science, 2A & 2B, Raja S.C. Mullick Road, 700032, Kolkata, India
Received:
23
May
2023
Accepted:
20
August
2024
Published online:
14
September
2024
Exotic spin-0 states with unusual couplings with the gauge and matter fields of the Standard Model are worth exploring at the CERN LHC. Though our approach is largely model independent, we take inspiration from flavor models based on some discrete symmetries which predict a set of a scalar and a pseudoscalar having purely off-diagonal Yukawa interactions with quarks and leptons. In a previous paper, some of us explored how to decipher such exotic scalar and pseudoscalar states whose off-diagonal Yukawa couplings involve light quarks. In this work we follow a complementary path and focus on the Yukawa couplings that necessarily involve a top quark. If one such spin-0 state is lighter than the top quark, then the rare decay of the latter, on account of the high yield of the 
events, could provide a potential hunting ground of those exotic states particularly during the high luminosity phase of the LHC run. We carry out an exhaustive collider analysis of some promising signatures of those exotic states using sophisticated Machine Learning techniques and obtain considerable signal significance.
© The Author(s) 2024
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Funded by SCOAP3.
