Non-relativistic leptogenesis

Abstract

In many phenomenologically interesting models of thermal leptogenesis the heavy neutrinos are non-relativistic when they decay and produce the baryon asymmetry of the Universe. We propose a non-relativistic approximation for the corresponding rate equations in the non-resonant case, and a systematic way for computing relativistic corrections. We determine the leading order coefficients in these equations, and the first relativistic corrections. The non-relativistic approximation works remarkably well. It appears to be consistent with results obtained using a Boltzmann equation taking into account the momentum distribution of the heavy neutrinos, while being much simpler. We also compute radiative corrections to some of the coefficients in the rate equations. Their effect is of order 1% in the regime favored by neutrino oscillation data. We obtain the correct leading order lepton number washout rate in this regime, which leads to large (~ 20%) effects compared to previous computations.

19 pages, 5 figures. Presentation of the numerical results slightly rearranged to improve the line of arguments why full momentum dependent Boltzmann equation is unnecessary, one reference added, journal version

References in corpus (3)

• Leptogenesis
• Full Boltzmann equations for leptogenesis including scattering
• On the full Boltzmann equations for Leptogenesis

Cited by in corpus (16)

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• Kubo relations and radiative corrections for lepton number washout
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• Precision study of GeV-scale resonant leptogenesis
• Equilibration, particle production, and self-energy
• A QCD Debye mass in a broad temperature range
• Strong thermal leptogenesis and the absolute neutrino mass scale
• CP asymmetry in heavy Majorana neutrino decays at finite temperature: the hierarchical case
• CP asymmetry in heavy Majorana neutrino decays at finite temperature: the nearly degenerate case
• Kinetic equations for sterile neutrinos from thermal fluctuations
• Lepton asymmetry rate from quantum field theory: NLO in the hierarchical limit
• A full analytic solution of $SO(10)$-inspired leptogenesis
• Complete leading-order standard model corrections to quantum leptogenesis
• Sterile neutrino rates for general $M$, $T$, $\mu$, $k$: review of a theoretical framework