- April 14, 2022, 2:30 pm US/Central
- Asli Abdullahi, Fermilab
The recent measurement of the anomalous muon magnetic moment by the E989 experiment at Fermilab appears to confirm the existing tension with the Standard Model (SM), previously reported by the Brookhaven experiment. In light of this result, we revisit the contribution of a kinetically mixed dark photon to g-2, which has been excluded in minimal models with fully visible or fully invisible dark photon decays. Explicitly re-evaluating constraints from B-factories and fixed-target experiments, we show that dark photons with semi-visible decays can still explain the g-2 puzzle and that such a solution would point to dark sectors with co-annihilating dark matter candidates or dark heavy neutral leptons with fast decays.