In the March 12th, 2021 issue of Physical Review Letters, the BESIII collaboration reports the discovery of an exotic multi-quark structure, dubbed the Zcs(3985), that is produced in the process of e+ e-→K+ (Ds- D*0+Ds*-D0) at an e+ e- center-of-mass energy of 4.68 GeV. The Zcs(3985) is observed to decay to a charged strange-charmed meson plus a neutral charmed meson, i.e., Ds- D*0+Ds*-D0, and has a mass of 3.98 GeV/c2.
This is the first candidate for a tetra-quark meson containing hidden-charm with non-zero strangeness. This paper was selected as an "Editors' Suggestion" for that issue of the journal and was prominently featured on the APS synopsis website.
Full press release: http://bes3.ihep.ac.cn/doc/4187.html