Newest results on XYZ states at BESIII

Abstract

The BESIII experiment at BEPCII at IHEP in Beijing/China has collected the world largest data sets in the $\tau$-charm region and it is well suited to cover a rich hadron physics programme, including charmonium and open-charm spectroscopy, $R$-scan or electromagnetic form factor measurements, and many more. In particular, the unique data sets between 3.8 and 4.6\,GeV allow for discoveries and precision measurements of the interesting charmonium-like (exotic) `XYZ' states. The recently published precision cross-section measurement for $Y$ states is discussed as well as the first observation of the $X(3872)$ in radiative decays, also the completion of the two observed isospin triplets $Z_{\rm c}(3900)$ and $Z_{\rm c}(4020)$ is briefly summarised.