17–21 Aug 2026
University of Helsinki Main Building
Europe/Helsinki timezone

Baryon number violation from Standard Model Higgs bubble collisions

19 Aug 2026, 12:00
15m
F4050 (4th floor) (University of Helsinki Main Building)

F4050 (4th floor)

University of Helsinki Main Building

University of Helsinki Fabianinkatu 33 Finland
talk (15min) Early universe physics, inflation, electroweak phase transitions, and sources for gravitational waves Early Universe Contributions 1

Speaker

Nabeen Bhusal (DESY)

Description

Baryon number violation at the electroweak (EW) phase transition has typically been associated with thermal sphalerons in the Standard Model (SM). We showed in [2508.21825, to appear in PRL] that B-violation can also occur at zero temperature from a supercooled first-order electroweak phase transition.
In this talk, I will review the work done on B-violation from the production of EW textures in quenched tachyonic EW phase transitions and present our new mechanism in which baryon number violation can occur at zero temperature from Higgs bubble collisions, showing that this can be of the same order as that from thermal sphalerons in the symmetric phase at EW temperatures. I will highlight the dependence of the rate of Chern–Simons number transitions on the shape of the scalar potential and on the Lorentz factor of the bubble walls at collision, as calculated via large-scale $(3+1)D$ lattice simulations of the Higgs doublet and $SU(2)$ gauge fields.

Authors

Aleksandr Chatrchyan (Nordita) Geraldine Servant (Deutsches Elektronen-Synchrotron (DE)) Marco Gorghetto Martina Cataldi (University of Hamburg) Nabeen Bhusal (DESY) Dr Simone Blasi (DESY)

Presentation materials

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