Speaker
Description
Direct detection experiments have imposed stringent experimental constraints on dark matter with masses greater than 1 GeV, while much looser limits apply to lighter sub-GeV dark matter due to their non-relativistic velocities, which prevent them from reaching the detection thresholds of most traditional experimental methods. BESIII is a general-purpose detector operating at BEPCII with center-of-mass energies of a few GeV, providing unique opportunities to study sub-GeV dark matter. By utilizing the known initial four-momentum and full reconstruction capabilities, BESIII can employ missing mass or missing energy techniques to search for invisible dark matter generated from the collider. In this talk, I will present some of the latest results on dark matter from BESIII, including searches for $\eta\to\pi^0+\rm{invisible}$, $J/\psi\to\phi+\rm{invisible}$, and $K^0_S\to\rm{invisible}$. Additionally, I will report on the study of exotic dark matter carrying a baryon number in $\Xi^-\to\pi^-+\rm{invisible}$. These results can provide unique and stringent constraints on sub-GeV dark matter.