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High Energy Phenomenology Seminar: Seth Koren (UChicago) "Discrete Gauged Baryon Minus Lepton Number and the Cosmological Lithium Problem"

Event Type
Department of Physics
Room 464
Sep 9, 2022   11:00 am  
Seth Koren (UChicago)
Brandy Koebbe
Originating Calendar
Physics - High Energy Phenomenology Seminar

We study the baryon minus lepton number gauge theory broken by a scalar with charge six. The infrared discrete vestige of the gauge symmetry demands the existence of cosmic string solutions, and their production as dynamical objects in the early universe is guaranteed by causality. These topological defects can support interactions which convert three protons into three positrons, and we argue an `electric'-`magnetic' interplay can lead to an amplified, strong-scale cross-section in an analogue of the Callan-Rubakov effect.

The cosmological lithium problem---that theory predicts a primordial abundance thrice as high as that observed---has resisted decades of attempts by cosmologists, nuclear physicists, and astronomers alike to root out systematics. We suggest cosmic strings have disintegrated O(1) of the primordial lithium nuclei and estimate the rate in a benchmark scenario.

To our knowledge this is the first new physics mechanism with microphysical justification for the abundance of lithium uniquely to be modified after Big Bang Nucleosynthesis.

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