Speaker
Description
Axion-like particles (ALPs) are pseudo-Goldstone bosons arising from some spontaneously broken global symmetry, addressing the strong CP or hierarchy problems. The BESIII experiment is a symmetric e+e- collider operating at c.m. energy from 2.0 to 4.95 GeV. With the world’s largest data set of $J/\psi$ (10 Billion), $\psi(2S)$ (2.6 Billion), and about 25 fb-1 scan data from 3.77 to 4.95 GeV, we are able to search various dark sectors particles produced in e+e- annihilation and meson decay processes. In this talk, we report the search for dark photon candidate in $e^+e^- \to \gamma A’$ with invisible decay. The invisible decay of a light Higgs boson $A^0$ in $J/\psi \to \gamma A^0$ and in $\Lambda/\Lambda_c$ decays is also searched. In addition we perform searches for an Axion-like particle with mass O(GeV) in $J/\psi \to \gamma A$, with $A \to \gamma gamma$.
