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Single-spin measurements and heavy new physics in the e+e−→tt¯ process at an FCC-ee

Haotian Cao1,2,* and Frank Petriello1,†

  • *Contact author: haotiao.cao@northwestern.edu
  • †Contact author: f-petriello@northwestern.edu
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Phys. Rev. D 113, 035033 – Published 24 February, 2026

DOI: https://doi.org/10.1103/794y-gp3r

Abstract

We investigate the potential of single-spin components of the spin-density matrix in the e+e−→tt¯ process at a future FCC-ee for probing heavy new physics parametrized using the Standard Model effective field theory (SMEFT) framework. We consider the full spectrum of spin observables and the complete angular decomposition of the tt¯ production process in our study. We find that single-spin measurements generically provide stronger probes of SMEFT Wilson coefficients than measurements where the tt¯ spins are correlated, and that single-spin observables are important for resolving flat directions that can appear in the Wilson-coefficient parameter space.

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References (63)

  1. T. Aaltonen et al. (CDF Collaboration), Phys. Rev. D 83, 031104 (2011).
  2. V. M. Abazov et al. (D0 Collaboration), Phys. Rev. Lett. 108, 032004 (2012).
  3. V. M. Abazov et al. (D0 Collaboration), Phys. Rev. Lett. 107, 032001 (2011).
  4. V. M. Abazov et al. (D0 Collaboration), Phys. Rev. D 87, 011103 (2013).
  5. V. Miralles, M. M. López, M. M. Llácer, A. Peñuelas, Martin Perelló, and M. Vos, J. High Energy Phys. 02 (2022) 032.
  6. G. Aad et al. (ATLAS Collaboration), Nature (London) 633, 542 (2024).
  7. A. Hayrapetyan et al. (CMS Collaboration), Rep. Prog. Phys. 87, 117801 (2024).
  8. G. Aad et al. (ATLAS Collaboration), Phys. Rev. D 90, 112016 (2014).
  9. V. Khachatryan et al. (CMS Collaboration), Phys. Lett. B 758, 321 (2016).
  10. V. Khachatryan et al. (CMS Collaboration), Phys. Rev. D 93, 052007 (2016).
  11. M. Aaboud et al. (ATLAS Collaboration), J. High Energy Phys. 03 (2017) 113.
  12. G. Aad et al. (ATLAS Collaboration), Eur. Phys. J. C 80, 528 (2020).
  13. M. Aaboud et al. (ATLAS Collaboration), Eur. Phys. J. C 80, 754 (2020).
  14. A. M. Sirunyan et al. (CMS Collaboration), Phys. Rev. D 100, 072002 (2019).
  15. A. Hayrapetyan et al. (CMS Collaboration), Phys. Rev. D 110, 112016 (2024).
  16. Q.-H. Cao, B. Yan, C. P. Yuan, and Y. Zhang, Phys. Rev. D 102, 055010 (2020).
  17. S. Bhattacharya, S. Jahedi, and J. Wudka, J. High Energy Phys. 12 (2023) 026.
  18. F. Maltoni, C. Severi, S. Tentori, and E. Vryonidou, J. High Energy Phys. 03 (2024) 099.
  19. A. J. Barr, M. Fabbrichesi, R. Floreanini, E. Gabrielli, and L. Marzola, Prog. Part. Nucl. Phys. 139, 104134 (2024).
  20. R. Aoude, E. Madge, F. Maltoni, and L. Mantani, Phys. Rev. D 106, 055007 (2022).
  21. C. Severi and E. Vryonidou, J. High Energy Phys. 01 (2023) 148.
  22. M. Fabbrichesi and L. Marzola, Phys. Rev. D 109, 095026 (2024).
  23. M. Fabbrichesi, R. Floreanini, and E. Gabrielli, Eur. Phys. J. C 83, 162 (2023).
  24. M. M. Altakach, P. Lamba, F. Maltoni, K. Mawatari, and K. Sakurai, Phys. Rev. D 107, 093002 (2023).
  25. R. Aoude, E. Madge, F. Maltoni, and L. Mantani, J. High Energy Phys. 12 (2023) 017.
  26. A. Bernal, P. Caban, and J. Rembieliński, Eur. Phys. J. C 83, 1050 (2023).
  27. M. Fabbrichesi, R. Floreanini, E. Gabrielli, and L. Marzola, J. High Energy Phys. 09 (2023) 195.
  28. Z. Dong, D. Gonçalves, K. Kong, and A. Navarro, Phys. Rev. D 109, 115023 (2024).
  29. M. Fabbrichesi, R. Floreanini, and G. Panizzo, Phys. Rev. Lett. 127, 161801 (2021).
  30. C. Severi, C. D. E. Boschi, F. Maltoni, and M. Sioli, Eur. Phys. J. C 82, 285 (2022).
  31. J. A. Aguilar-Saavedra and J. A. Casas, Eur. Phys. J. C 82, 666 (2022).
  32. Y. Afik and J. R. M. de Nova, Phys. Rev. Lett. 130, 221801 (2023).
  33. J. A. Aguilar-Saavedra, Phys. Rev. D 108, 076025 (2023).
  34. T. Han, M. Low, and T. A. Wu, J. High Energy Phys. 07 (2024) 192.
  35. J. A. Aguilar-Saavedra, Phys. Rev. D 109, 096027 (2024).
  36. F. Maltoni, C. Severi, S. Tentori, and E. Vryonidou, J. High Energy Phys. 09 (2024) 001.
  37. A. Brandenburg, Z. G. Si, and P. Uwer, Phys. Lett. B 539, 235 (2002).
  38. W. Bernreuther, A. Brandenburg, Z. G. Si, and P. Uwer, Nucl. Phys. B690, 81 (2004).
  39. W. Bernreuther, D. Heisler, and Z.-G. Si, J. High Energy Phys. 12 (2015) 026.
  40. W. Bernreuther, L. Chen, and Z.-G. Si, Phys. Rev. D 109, 116016 (2024).
  41. P. H. Khiem, E. Kou, Y. Kurihara, and F. Le Diberder, arXiv:1503.04247.
  42. A. Brandenburg, M. Flesch, and P. Uwer, Phys. Rev. D 59, 014001 (1999).
  43. P. Janot, J. High Energy Phys. 04 (2015) 182.
  44. L. Bellafronte, S. Dawson, P. P. Giardino, and H. Liu, Phys. Rev. Lett. 135, 251801 (2025).
  45. E. Vryonidou and C. Zhang, J. High Energy Phys. 08 (2018) 036.
  46. G. Durieux and O. Matsedonskyi, J. High Energy Phys. 01 (2019) 072.
  47. G. Durieux, J. Gu, E. Vryonidou, and C. Zhang, Chin. Phys. C 42, 123107 (2018).
  48. G. Durieux, M. Perelló, M. Vos, and C. Zhang, J. High Energy Phys. 10 (2018) 168.
  49. G. Durieux, A. Irles, V. Miralles, A. Peñuelas, M. Perelló, R. Pöschl, and M. Vos, J. High Energy Phys. 12 (2019) 098; 01 (2021) 195(E).
  50. S. Jung, J. Lee, M. Perelló, J. Tian, and M. Vos, Phys. Rev. D 105, 016003 (2022).
  51. G. Bernardi et al., arXiv:2203.06520.
  52. J. de Blas et al., Global SMEFT fits at future colliders, in Snowmass 2021 (2022), arXiv:2206.08326.
  53. G. Durieux et al., Snowmass White Paper: Prospects for the measurement of top-quark couplings, in Snowmass 2021 (2022), arXiv:2205.02140.
  54. G. Banelli, E. Salvioni, J. Serra, T. Theil, and A. Weiler, J. High Energy Phys. 02 (2021) 043.
  55. Y. Afik and J. R. M. de Nova, Eur. Phys. J. Plus 136, 907 (2021).
  56. M. Beneke, Y. Kiyo, A. Maier, and J. Piclum, Comput. Phys. Commun. 209, 96 (2016).
  57. S. A. Abel, H. K. Dreiner, R. Sengupta, and L. Ubaldi, arXiv:2507.15949.
  58. B. Grzadkowski, M. Iskrzynski, M. Misiak, and J. Rosiek, J. High Energy Phys. 10 (2010) 085.
  59. A. Buckley et al., J. High Energy Phys. 04 (2016) 015.
  60. R. Boughezal, C.-Y. Chen, F. Petriello, and D. Wiegand, Phys. Rev. D 100, 056023 (2019).
  61. M. M. Defranchis, J. de Blas, A. Mehta, M. Selvaggi, and M. Vos, J. High Energy Phys. 11 (2025) 020.
  62. M. Beneke, A. Maier, T. Rauh, and P. Ruiz-Femenia, J. High Energy Phys. 02 (2018) 125.
  63. B. Tweedie, Phys. Rev. D 90, 094010 (2014).

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Phys. Rev. D 113, 035033– Published 24 February, 2026
  • Received 10 November 2025
  • Accepted 5 February 2026
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