The doubly charmed strange tetraquark

The LHCb experiment at CERN has discovered a doubly charmed isoscalar tetraquark $T_{cc}$ with the quantum numbers of $cc\bar{u}\bar{d}$ and mass of about 3875 MeV/$c^2$, decaying to $D^0{D}^0{\pi }^{+}$ through the intermediate channel $D^{\ast +}{D}^0$. We present a study of its strange companions with the quantum numbers of $cc\bar{q}\bar{s}$, where $q=u,d$ and isospin violation is neglected.