A number of nuclear decay anomalies have been reported in the literature, which purport to show periodic variations in the decay rates of certain radioisotopes. If these reports reflect reality, they would necessitate a seismic shift in our understanding of fundamental physics. We provide the first mechanism to explain these findings, via the misalignment mechanism of QCD axion dark matter, wherein oscillations of the effective theta angle induce periodic variation in nuclear binding energies and hence decay rates. Expecting this effect to be most pronounced in low-Q systems, we analyse 12 years of tritium decay data (Q ≃ 18.6 keV) taken at the European Commission’s Joint Research Centre. Finding no statistically significant excess, we then place novel constraints on the corresponding axion parameter space.

Biography

Theoretical physicist, specialising in astroparticle physics and dark matter detection. Graduated King's College London PhD in 2015, followed by postdoctoral research at the ITP-CAS and Peking University, and then joined Beijing University of Technology (北京工业大学) in 2019 as an associate professor.

Inviter: Tian-Jun Li