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Interpretation of LHC excesses at 95 GeV and 152 GeV in an extended Georgi-Machacek model

Ting-Kuo Chen1,*, Cheng-Wei Chiang2,3,†, Sven Heinemeyer4,‡, and Georg Weiglein5,6,§

  • *Contact author: tchen463@wisc.edu
  • †Contact author: chengwei@phys.ntu.edu.tw
  • ‡Contact author: sven.heinemeyer@cern.ch
  • §Contact author: georg.weiglein@desy.de
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Phys. Rev. D 113, 075027 – Published 24 April, 2026

DOI: https://doi.org/10.1103/xzl4-1fh1

Abstract

We analyze the excesses at 95 GeV in the light Higgs-boson searches in the diphoton decay channel reported by CMS and ATLAS, which combined are at the level of three standard deviations and are compatible with the excess in the bb¯ final state observed at Large Electron-Positron Collider, together with an excess in the diphoton channel at around 152 GeV reported based on a sideband analysis. We demonstrate that these excesses can be well described in a minimally extended Georgi-Machacek (meGM) model. This is enabled by four key features of the meGM model: (1) a natural prediction for scalar boson masses of ≲200  GeV arising from the condition to describe both the Higgs boson signal at 125 GeV and the excesses at 95 GeV, (2) the prediction for a doubly charged Higgs boson that can potentially enhance the diphoton decay rates, (3) asymmetric WW and ZZ couplings to neutral scalar bosons that are induced by mild custodial symmetry breaking, and (4) the approximate preservation of the electroweak ρ parameter to be 1 at tree level. We show in our numerical analysis that the meGM model naturally improves the fit to the LHC data around 152 GeV when describing the excesses at 95 GeV. At the same time, the model also predicts additional light CP-odd and charged scalar bosons that can be potentially probed in future experiments, which motivates dedicated searches in the upcoming LHC runs. We also present the results of sensitivity studies for the 95 and 125 GeV Higgs-boson couplings at the HL-LHC and future e+e− colliders, which demonstrate very interesting prospects for probing the meGM model at future colliders.

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References (109)

  1. G. Aad et al. (ATLAS Collaboration), Phys. Lett. B 716, 1 (2012).
  2. S. Chatrchyan et al. (CMS Collaboration), Phys. Lett. B 716, 30 (2012).
  3. A. Tumasyan et al. (CMS Collaboration), Nature (London) 607, 60 (2022).
  4. G. Aad et al. (ATLAS Collaboration), Nature (London) 607, 52 (2022); 612, E24(E) (2022).
  5. Search for a standard model-like Higgs boson in the mass range between 70 and 110 GeV in the diphoton final state in proton-proton collisions at s=13  TeV, Techical Report Nos. CMS-HIG-17-013, CERN-EP-2018-207, CERN, Geneva, 2023.
  6. Search for diphoton resonances in the 66 to 110 GeV mass range using 140  fb−1 of 13 TeV pp collisions collected with the ATLAS detector, Techical Report No. CMS-PAS-EXO-21-018, CERN, Geneva, 2023.
  7. T. Biekötter, S. Heinemeyer, and G. Weiglein, Phys. Rev. D 109, 035005 (2024).
  8. R. Barate et al. (LEP Working Group for Higgs boson searches, ALEPH Collaboration, DELPHI Collaboration, L3 Collaboration, and OPAL Collaboration), Phys. Lett. B 565, 61 (2003).
  9. J. Cao, X. Guo, Y. He, P. Wu, and Y. Zhang, Phys. Rev. D 95, 116001 (2017).
  10. A. Azatov, R. Contino, and J. Galloway, J. High Energy Phys. 04 (2012) 127; 04 (2013) 140(E).
  11. A. Tumasyan et al. (CMS Collaboration), J. High Energy Phys. 07 (2023) 073.
  12. Search for dilepton resonances from decays of (pseudo)scalar bosons produced in association with a massive vector boson or top quark anti-top quark pair at s=13  TeV, Techical Report No. CMS-PAS-EXO-21-018, CERN, Geneva, 2022.
  13. A. Belyaev, R. Benbrik, M. Boukidi, M. Chakraborti, S. Moretti, and S. Semlali, J. High Energy Phys. 05 (2024) 209.
  14. J. A. Aguilar-Saavedra, H. B. Câmara, F. R. Joaquim, and J. F. Seabra, Phys. Rev. D 108, 075020 (2023).
  15. J. Dutta, J. Lahiri, C. Li, G. Moortgat-Pick, S. F. Tabira, and J. A. Ziegler, Eur. Phys. J. C 84, 926 (2024).
  16. U. Ellwanger and C. Hugonie, Eur. Phys. J. C 83, 1138 (2023).
  17. J. Cao, X. Jia, J. Lian, and L. Meng, Phys. Rev. D 109, 075001 (2024).
  18. G. Arcadi, G. Busoni, D. Cabo-Almeida, and N. Krishnan, Phys. Rev. D 110, 115028 (2024).
  19. A. Ahriche, Phys. Rev. D 110, 035010 (2024).
  20. T.-K. Chen, C.-W. Chiang, S. Heinemeyer, and G. Weiglein, Phys. Rev. D 109, 075043 (2024).
  21. P. S. B. Dev, R. N. Mohapatra, and Y. Zhang, Phys. Lett. B 849, 138481 (2024).
  22. C.-X. Liu, Y. Zhou, X.-Y. Zheng, J. Ma, T.-F. Feng, and H.-B. Zhang, Phys. Rev. D 109, 056001 (2024).
  23. J. Cao, X. Jia, and J. Lian, Phys. Rev. D 110, 115039 (2024).
  24. J. Kalinowski and W. Kotlarski, J. High Energy Phys. 07 (2024) 037.
  25. U. Ellwanger and C. Hugonie, Eur. Phys. J. C 84, 526 (2024).
  26. U. Ellwanger, C. Hugonie, S. F. King, and S. Moretti, Eur. Phys. J. C 84, 788 (2024).
  27. A. Arhrib, K. H. Phan, V. Q. Tran, and T.-C. Yuan, Nucl. Phys. B1015, 116909 (2025).
  28. R. Benbrik, M. Boukidi, and S. Moretti, Phys. Rev. D 110, 115030 (2024).
  29. J. Lian, Phys. Rev. D 110, 115018 (2024).
  30. S. Ghosh, arXiv:2501.17457.
  31. X. Du, H. Liu, and Q. Chang, Phys. Rev. D 112, 015019 (2025).
  32. R. Benbrik, M. Boukidi, K. Kahime, S. Moretti, L. Rahili, and B. Taki, Phys. Lett. B 868, 139688 (2025).
  33. T. Biekötter, S. Heinemeyer, and C. Muñoz, Eur. Phys. J. C 78, 504 (2018).
  34. F. Domingo, S. Heinemeyer, S. Paßehr, and G. Weiglein, Eur. Phys. J. C 78, 942 (2018).
  35. T. Biekötter, M. Chakraborti, and S. Heinemeyer, Eur. Phys. J. C 80, 2 (2020).
  36. T. Biekötter, A. Grohsjean, S. Heinemeyer, C. Schwanenberger, and G. Weiglein, Eur. Phys. J. C 82, 178 (2022).
  37. T. Biekötter, S. Heinemeyer, and G. Weiglein, J. High Energy Phys. 08 (2022) 201.
  38. T. Biekötter, S. Heinemeyer, and G. Weiglein, Phys. Lett. B 846, 138217 (2023).
  39. H. Georgi and M. Machacek, Nucl. Phys. B262, 463 (1985).
  40. M. S. Chanowitz and M. Golden, Phys. Lett. 165B, 105 (1985).
  41. A. Kundu, P. Mondal, and G. Moultaka, arXiv:2411.14126.
  42. P. Mondal and S. Samanta, arXiv:2506.06427.
  43. A. Crivellin, Y. Fang, O. Fischer, S. Bhattacharya, M. Kumar, E. Malwa, B. Mellado, N. Rapheeha, X. Ruan, and Q. Sha, Phys. Rev. D 108, 115031 (2023).
  44. G. Coloretti, A. Crivellin, S. Bhattacharya, and B. Mellado, Phys. Rev. D 108, 035026 (2023).
  45. S. Banik, G. Coloretti, A. Crivellin, and B. Mellado, J. High Energy Phys. 01 (2025) 155.
  46. S. Bhattacharya, G. Coloretti, A. Crivellin, S.-E. Dahbi, Y. Fang, M. Kumar, and B. Mellado, arXiv:2306.17209.
  47. S. Ashanujjaman, S. Banik, G. Coloretti, A. Crivellin, S. P. Maharathy, and B. Mellado, Phys. Lett. B 862, 139298 (2025).
  48. A. Crivellin, S. Ashanujjaman, S. Banik, G. Coloretti, S. P. Maharathy, and B. Mellado, Chin. Phys. C 49, 053107 (2025).
  49. S. Banik, G. Coloretti, A. Crivellin, and H. E. Haber, Phys. Rev. D 111, 075021 (2025).
  50. S. Ashanujjaman, S. Banik, G. Coloretti, A. Crivellin, S. P. Maharathy, and B. Mellado, J. High Energy Phys. 04 (2025) 003.
  51. S. Ashanujjaman, A. Crivellin, S. P. Maharathy, and A. Thapa, Phys. Rev. D 112, 035040 (2025).
  52. S. Bhattacharya, B. Lieberman, M. Kumar, A. Crivellin, Y. Fang, R. Mazini, and B. Mellado, arXiv:2503.16245.
  53. T.-K. Chen, C.-W. Chiang, and K. Yagyu, J. High Energy Phys. 06 (2023) 069; 07 (2023) 169(E).
  54. S. Navas et al. (Particle Data Group), Phys. Rev. D 110, 030001 (2024).
  55. T. Aaltonen et al. (CDF Collaboration), Science 376, 170 (2022).
  56. T.-K. Chen, C.-W. Chiang, and K. Yagyu, Phys. Rev. D 106, 055035 (2022).
  57. S. Blasi, S. De Curtis, and K. Yagyu, Phys. Rev. D 96, 015001 (2017).
  58. B. Keeshan, H. E. Logan, and T. Pilkington, Phys. Rev. D 102, 015001 (2020).
  59. T. P. Cheng and L.-F. Li, Phys. Rev. D 22, 2860 (1980).
  60. J. Schechter and J. W. F. Valle, Phys. Rev. D 22, 2227 (1980).
  61. M. Magg and C. Wetterich, Phys. Lett. 94B, 61 (1980).
  62. R. N. Mohapatra and G. Senjanovic, Phys. Rev. D 23, 165 (1981).
  63. G. Moultaka and M. C. Peyranère, Phys. Rev. D 103, 115006 (2021).
  64. W. G. Hollik, G. Weiglein, and J. Wittbrodt, J. High Energy Phys. 03 (2019) 109.
  65. P. M. Ferreira, M. Mühlleitner, R. Santos, G. Weiglein, and J. Wittbrodt, J. High Energy Phys. 09 (2019) 006.
  66. T. Biekötter, S. Heinemeyer, and G. Weiglein, Eur. Phys. J. C 82, 301 (2022).
  67. D. Chowdhury, P. Mondal, and S. Samanta, arXiv:2404.18996.
  68. J. M. Cornwall, D. N. Levin, and G. Tiktopoulos, Phys. Rev. D 10, 1145 (1974); 11, 972(E) (1975).
  69. S. von Buddenbrock, N. Chakrabarty, A. S. Cornell, D. Kar, M. Kumar, T. Mandal, B. Mellado, B. Mukhopadhyaya, R. G. Reed, and X. Ruan, Eur. Phys. J. C 76, 580 (2016).
  70. S. von Buddenbrock, A. S. Cornell, A. Fadol, M. Kumar, B. Mellado, and X. Ruan, J. Phys. G 45, 115003 (2018).
  71. S. Buddenbrock, A. S. Cornell, Y. Fang, A. Fadol Mohammed, M. Kumar, B. Mellado, and K. G. Tomiwa, J. High Energy Phys. 10 (2019) 157.
  72. S. von Buddenbrock, R. Ruiz, and B. Mellado, Phys. Lett. B 811, 135964 (2020).
  73. Y. Hernandez, M. Kumar, A. S. Cornell, S.-E. Dahbi, Y. Fang, B. Lieberman, B. Mellado, K. Monnakgotla, X. Ruan, and S. Xin, Eur. Phys. J. C 81, 365 (2021).
  74. G. Coloretti, A. Crivellin, and B. Mellado, Phys. Rev. D 110, 073001 (2024).
  75. A. M. Sirunyan et al. (CMS Collaboration), J. High Energy Phys. 07 (2021) 027.
  76. G. Aad et al. (ATLAS Collaboration), J. High Energy Phys. 07 (2023) 088.
  77. G. Aad et al. (ATLAS Collaboration), Phys. Rev. Lett. 125, 061802 (2020).
  78. A. M. Sirunyan et al. (CMS Collaboration), Phys. Rev. Lett. 125, 061801 (2020).
  79. G. Aad et al. (ATLAS Collaboration), J. High Energy Phys. 10 (2021) 013.
  80. A. M. Sirunyan et al. (CMS Collaboration), J. High Energy Phys. 09 (2018) 046.
  81. A. M. Sirunyan et al. (CMS Collaboration), J. High Energy Phys. 11 (2018) 152.
  82. G. Aad et al. (ATLAS Collaboration), Eur. Phys. J. C 81, 178 (2021).
  83. S. Banik and A. Crivellin, J. High Energy Phys. 10 (2024) 203.
  84. G. Aad et al. (ATLAS Collaboration), J. High Energy Phys. 07 (2023) 176.
  85. G. Aad et al. (ATLAS Collaboration), J. High Energy Phys. 08 (2024) 164.
  86. J. Alwall, R. Frederix, S. Frixione, V. Hirschi, F. Maltoni, O. Mattelaer, H. S. Shao, T. Stelzer, P. Torrielli, and M. Zaro, J. High Energy Phys. 07 (2014) 079.
  87. R. Frederix, S. Frixione, V. Hirschi, D. Pagani, H. S. Shao, and M. Zaro, J. High Energy Phys. 07 (2018) 185; 11 (2021) 085(E).
  88. T. Sjöstrand, S. Ask, J. R. Christiansen, R. Corke, N. Desai, P. Ilten, S. Mrenna, S. Prestel, C. O. Rasmussen, and P. Z. Skands, Comput. Phys. Commun. 191, 159 (2015).
  89. J. de Favereau, C. Delaere, P. Demin, A. Giammanco, V. Lemaître, A. Mertens, and M. Selvaggi (DELPHES 3 Collaboration), J. High Energy Phys. 02 (2014) 057.
  90. M. Cacciari, G. P. Salam, and G. Soyez, J. High Energy Phys. 04 (2008) 063.
  91. M. Cacciari, G. P. Salam, and G. Soyez, Eur. Phys. J. C 72, 1896 (2012).
  92. J. De Blas et al., Eur. Phys. J. C 80, 456 (2020).
  93. H. Bahl, T. Biekötter, S. Heinemeyer, C. Li, S. Paasch, G. Weiglein, and J. Wittbrodt, Comput. Phys. Commun. 291, 108803 (2023).
  94. P. Bechtle, S. Heinemeyer, O. Stål, T. Stefaniak, and G. Weiglein, Eur. Phys. J. C 74, 2711 (2014).
  95. P. Bechtle, S. Heinemeyer, O. Stål, T. Stefaniak, and G. Weiglein, J. High Energy Phys. 11 (2014) 039.
  96. P. Bechtle, S. Heinemeyer, T. Klingl, T. Stefaniak, G. Weiglein, and J. Wittbrodt, Eur. Phys. J. C 81, 145 (2021).
  97. P. Bechtle, O. Brein, S. Heinemeyer, G. Weiglein, and K. E. Williams, Comput. Phys. Commun. 181, 138 (2010).
  98. P. Bechtle, O. Brein, S. Heinemeyer, G. Weiglein, and K. E. Williams, Comput. Phys. Commun. 182, 2605 (2011).
  99. P. Bechtle, O. Brein, S. Heinemeyer, O. Stål, T. Stefaniak, G. Weiglein, and K. E. Williams, Eur. Phys. J. C 74, 2693 (2014).
  100. P. Bechtle, D. Dercks, S. Heinemeyer, T. Klingl, T. Stefaniak, G. Weiglein, and J. Wittbrodt, Eur. Phys. J. C 80, 1211 (2020).
  101. J. de Blas et al., 10.17181/CERN.35CH.2O2P (2025).
  102. P. Ferrari et al. (ATLAS Collaboration and CMS Collaboration), Highlights of the HL-LHC physics projections by ATLAS and CMS, Tech. Rep., 2025.
  103. P. Bambade et al., arXiv:1903.01629.
  104. J. List et al. (LCV Collaboration), A Linear Collider Vision for the Future of Particle Physics, Tech. Rep., LCVision, 2025.
  105. P. Drechsel, G. Moortgat-Pick, and G. Weiglein, Eur. Phys. J. C 80, 922 (2020).
  106. Y. Wang, J. List, and M. Berggren, arXiv:1801.08164.
  107. B. Brudnowski, K. Zembaczyński, and A. F. Żarnecki, EPJ Web Conf. 315, 01026 (2024).
  108. J. de Blas et al., arXiv:2401.07564.
  109. S. Heinemeyer, C. Li, F. Lika, G. Moortgat-Pick, and S. Paasch, Phys. Rev. D 106, 075003 (2022).

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Phys. Rev. D 113, 075027– Published 24 April, 2026
  • Received 17 November 2025
  • Accepted 11 March 2026
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