31 August 2026 to 4 September 2026
Australia/Sydney timezone

Baryon number freeze-out in the Standard Model, precisely

1 Sept 2026, 11:30
30m
Plenary Plenary

Speaker

Philipp Schicho (University of Geneva)

Description

The observed baryon asymmetry of the Universe provides a fundamental probe of high-scale physics and the thermal history of the electroweak plasma. Within the Standard Model, sphaleron processes partially convert a primordial $B-L$ asymmetry into baryon number, and the corresponding sphaleron conversion factor is a key ingredient in quantitative predictions of baryogenesis scenarios.

In this talk, I go beyond the equilibrium treatment and solve a Boltzmann equation describing the evolution of baryon number through the electroweak crossover. By incorporating higher-order corrections to the grand canonical partition function, as well as the temperature dependence of the Higgs expectation value and the sphaleron rate, I present a precision determination of the sphaleron conversion factor and assess the impact of flavor effects.

Author

Philipp Schicho (University of Geneva)

Presentation materials

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