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  • Letter
  • Open Access

Primordial Dirac leptogenesis

Aqeel Ahmed*, Juan P. Garcés†, and Manfred Lindner‡

  • *Contact author: aqeel.ahmed@mpi-hd.mpg.de
  • †Contact author: juan.garces@mpi-hd.mpg.de
  • ‡Contact author: lindner@mpi-hd.mpg.de
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Phys. Rev. D 113, L111702 – Published 10 June, 2026

DOI: https://doi.org/10.1103/bnfj-ypx8

Abstract

We present a novel realization of Dirac leptogenesis based on the postinflationary reheating phase of the early Universe. An asymmetry generated within the scalar sector via CP-violating and out-of-equilibrium inflaton decays is transferred to chiral neutrinos through Yukawa interactions and then to baryons via electroweak sphalerons. We describe in detail a minimal realization of this mechanism that naturally accommodates small neutrino Yukawa couplings and results in contributions to the effective number of relativistic species, Neff, testable in upcoming cosmological observations.

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Outline

Information

Phys. Rev. D 113, L111702– Published 10 June, 2026
  • Received 7 January 2026
  • Accepted 11 May 2026
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