Can a pseudoscalar with a mass of 365 GeV in two-Higgs-doublet models explain the CMS tt¯ excess?

We investigate the recently reported tt¯ excess by the CMS Collaboration within the framework of conventional Two-Higgs-Doublet Models (2HDMs). Considering all four types (I, II, X, and Y), we perform a comprehensive parameter space scan using the best-fit values for a pseudoscalar boson A: MA=365 G...

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Main Authors: Chih-Ting Lu, Kingman Cheung, Dongjoo Kim, Soojin Lee, Jeonghyeon Song
Format: Article
Language:English
Published: Elsevier 2024-12-01
Series:Physics Letters B
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Online Access:http://www.sciencedirect.com/science/article/pii/S0370269324006798
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author Chih-Ting Lu
Kingman Cheung
Dongjoo Kim
Soojin Lee
Jeonghyeon Song
author_facet Chih-Ting Lu
Kingman Cheung
Dongjoo Kim
Soojin Lee
Jeonghyeon Song
author_sort Chih-Ting Lu
collection DOAJ
description We investigate the recently reported tt¯ excess by the CMS Collaboration within the framework of conventional Two-Higgs-Doublet Models (2HDMs). Considering all four types (I, II, X, and Y), we perform a comprehensive parameter space scan using the best-fit values for a pseudoscalar boson A: MA=365 GeV, ΓA/MA=2%, and tan⁡β=1.28. Theoretical requirements and experimental constraints are systematically applied, including conditions from a bounded-below scalar potential, vacuum stability, unitarity, perturbativity, Flavor-Changing Neutral Currents (FCNCs), and direct searches at high-energy colliders. Our analysis shows that perturbativity imposes upper bounds of around 723 GeV on MH± and MH. FCNC constraints exclude all viable parameter space in Types II and Y, while a small region persists in Types I and X, but this region is ultimately ruled out by recent tt¯Z measurements by the ATLAS and CMS Collaborations at the LHC. We conclude that conventional 2HDMs alone cannot accommodate a pseudoscalar boson that explains the observed tt¯ excess within viable parameter space. However, incorporating toponium effects in the background fit could potentially alter this conclusion.
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series Physics Letters B
spelling doaj-art-abbf79f206544f818cbc0ae2e55eea852024-11-30T07:08:54ZengElsevierPhysics Letters B0370-26932024-12-01859139121Can a pseudoscalar with a mass of 365 GeV in two-Higgs-doublet models explain the CMS tt¯ excess?Chih-Ting Lu0Kingman Cheung1Dongjoo Kim2Soojin Lee3Jeonghyeon Song4Department of Physics and Institute of Theoretical Physics, Nanjing Normal University, Nanjing, 210023, ChinaDepartment of Physics, Konkuk University, Seoul 05029, Republic of Korea; Department of Physics, National Tsing Hwa University, Hsinchu 300, Taiwan; Center for Theory and Computation, National Tsing Hua University, Hsinchu 300, Taiwan; Corresponding authors.Department of Physics, Konkuk University, Seoul 05029, Republic of KoreaDepartment of Physics, Konkuk University, Seoul 05029, Republic of KoreaDepartment of Physics, Konkuk University, Seoul 05029, Republic of Korea; Corresponding authors.We investigate the recently reported tt¯ excess by the CMS Collaboration within the framework of conventional Two-Higgs-Doublet Models (2HDMs). Considering all four types (I, II, X, and Y), we perform a comprehensive parameter space scan using the best-fit values for a pseudoscalar boson A: MA=365 GeV, ΓA/MA=2%, and tan⁡β=1.28. Theoretical requirements and experimental constraints are systematically applied, including conditions from a bounded-below scalar potential, vacuum stability, unitarity, perturbativity, Flavor-Changing Neutral Currents (FCNCs), and direct searches at high-energy colliders. Our analysis shows that perturbativity imposes upper bounds of around 723 GeV on MH± and MH. FCNC constraints exclude all viable parameter space in Types II and Y, while a small region persists in Types I and X, but this region is ultimately ruled out by recent tt¯Z measurements by the ATLAS and CMS Collaborations at the LHC. We conclude that conventional 2HDMs alone cannot accommodate a pseudoscalar boson that explains the observed tt¯ excess within viable parameter space. However, incorporating toponium effects in the background fit could potentially alter this conclusion.http://www.sciencedirect.com/science/article/pii/S0370269324006798Higgs physicsBeyond the Standard ModelElectroweak precision data
spellingShingle Chih-Ting Lu
Kingman Cheung
Dongjoo Kim
Soojin Lee
Jeonghyeon Song
Can a pseudoscalar with a mass of 365 GeV in two-Higgs-doublet models explain the CMS tt¯ excess?
Physics Letters B
Higgs physics
Beyond the Standard Model
Electroweak precision data
title Can a pseudoscalar with a mass of 365 GeV in two-Higgs-doublet models explain the CMS tt¯ excess?
title_full Can a pseudoscalar with a mass of 365 GeV in two-Higgs-doublet models explain the CMS tt¯ excess?
title_fullStr Can a pseudoscalar with a mass of 365 GeV in two-Higgs-doublet models explain the CMS tt¯ excess?
title_full_unstemmed Can a pseudoscalar with a mass of 365 GeV in two-Higgs-doublet models explain the CMS tt¯ excess?
title_short Can a pseudoscalar with a mass of 365 GeV in two-Higgs-doublet models explain the CMS tt¯ excess?
title_sort can a pseudoscalar with a mass of 365 gev in two higgs doublet models explain the cms tt¯ excess
topic Higgs physics
Beyond the Standard Model
Electroweak precision data
url http://www.sciencedirect.com/science/article/pii/S0370269324006798
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