[tw-hepnet] NCTS Seminar - Particle Physics Journal Club 2026/06/08 (Mon.) 12:30

[Yu-Rou Tsang]

***NCTS Seminar***

Particle Physics Journal Club

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Speaker: Prof. Raymond Co (Indiana University)

Talk title: Dark Matter and Baryon Asymmetry from Axion Rotation with Dark Magnetic Monopoles

Time: 2026/06/08 (Mon.) 12:30

Place: NCTS Physics 4F Lecture Hall, Cosmology Hall, NTU

 

Abstract:
We propose a framework in which the QCD axion simultaneously accounts for the baryon asymmetry and contributes to dark matter through its early-universe rotation. A Peccei–Quinn (PQ) field rotation corresponds to a conserved PQ charge, which can be transferred to baryon number via sphaleron processes (axiogenesis) and to the axion abundance through its kinetic energy (the kinetic misalignment mechanism). However, a rotating axion field that generates the observed baryon asymmetry via axiogenesis typically overproduces axion dark matter via kinetic misalignment. We present a model in which this excess abundance is reduced by interactions with dark magnetic monopoles. We show that monopole—axion couplings induce transitions between dyonic levels that efficiently dissipate the axion’s kinetic energy into dark fermions. The resulting cosmology features a multi-component dark matter sector consisting of axions, monopoles, and dark fermions with comparable energy densities. The viable parameter space requires an axion decay constant below ~10^9 GeV.