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  • Open Access

Testing leptogenesis from observable gravitational waves

Wei Liu1,* and Yongcheng Wu2,3,†

  • 1Department of Applied Physics and MIIT Key Laboratory of Semiconductor Microstructure and Quantum Sensing, Nanjing University of Science and Technology, Nanjing 210094, China
  • 2Department of Physics, Institute of Theoretical Physics and Institute of Physics Frontiers and Interdisciplinary Sciences, Nanjing Normal University, Nanjing, 210023, China
  • 3Nanjing Key Laboratory of Particle Physics and Astrophysics, Nanjing, 210023, China

  • *Contact author: wei.liu@njust.edu.cn
  • †Contact author: ycwu@njnu.edu.cn
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Phys. Rev. D 114, 055025 – Published 14 September, 2026

DOI: https://doi.org/10.1103/69vn-4p32

Abstract

Leptogenesis provides an elegant mechanism to explain the observed baryon asymmetry of the Universe (BAU), yet its experimental verification remains challenging due to requirements of either extremely heavy right-handed neutrinos or precisely fine-tuned mass splittings. We present a scenario where an additional scalar field, coupled to both the Higgs and right-handed neutrinos (RHNs), enhances the CP asymmetry through loop-level contributions, enabling successful leptogenesis at the electroweak scale. This same scalar sector triggers a strong first-order electroweak phase transition (EWPT), producing gravitational waves (GWs) within the reach of next-generation detectors. We demonstrate a robust correlation between the BAU and GW signal strength, providing a falsifiable prediction of leptogenesis that future GW searches can confirm or rule out.

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Phys. Rev. D 114, 055025– Published 14 September, 2026
  • Received 9 June 2025
  • Revised 29 January 2026
  • Accepted 28 August 2026
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