A1 Journal article (refereed)
CP-violating transport theory for electroweak baryogenesis with thermal corrections (2021)

Kainulainen, K. (2021). CP-violating transport theory for electroweak baryogenesis with thermal corrections. Journal of Cosmology and Astroparticle Physics, 2021(11), Article 042. https://doi.org/10.1088/1475-7516/2021/11/042

JYU authors or editors

Publication details

All authors or editors: Kainulainen, Kimmo

Journal or series: Journal of Cosmology and Astroparticle Physics

eISSN: 1475-7516

Publication year: 2021

Volume: 2021

Issue number: 11

Article number: 042

Publisher: IOP Publishing

Publication country: United Kingdom

Publication language: English

DOI: https://doi.org/10.1088/1475-7516/2021/11/042

Publication open access: Not open

Publication channel open access: Channel is not openly available

Web address of parallel published publication (pre-print): https://arxiv.org/abs/2108.08336


We derive CP-violating transport equations for fermions for electroweak baryogenesis from the CTP-formalism including thermal corrections at the one-loop level. We consider both the VEV-insertion approximation (VIA) and the semiclassical (SC) formalism. We show that the VIA-method is based on an assumption that leads to an ill-defined source term containing a pinch singularity, whose regularisation by thermal effects leads to ambiguities including spurious ultraviolet and infrared divergences. We then carefully review the derivation of the semiclassical formalism and extend it to include thermal corrections. We present the semiclassical Boltzmann equations for thermal WKB-quasiparticles with source terms up to the second order in gradients that contain both dispersive and finite width corrections. We also show that the SC-method reproduces the current divergence equations and that a correct implementation of the Fick's law captures the semiclassical source term even with conserved total current ∂μjμ = 0. Our results show that the VIA-source term is not just ambiguous, but that it does not exist. Finally, we show that the collisional source terms reported earlier in the semiclassical literature are also spurious, and vanish in a consistent calculation.

Keywords: cosmology; particle physics

Free keywords: cosmology; astroparticle physics

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Ministry reporting: Yes

Preliminary JUFO rating: 1

Last updated on 2021-29-11 at 15:13