Speaker
Description
We present a calculation of exotic tetraquark states with two $\bar{b}$-quarks and of the lowest-energy $J^P=0^+$ and $1^+$ $B_s$-mesons using Lattice NRQCD. The calculations have been performed on the $N_f=2+1$ Wilson-Clover gauge-field configurations from the CLS consortium. For the $ud\bar{b}\bar{b}$ and $us\bar{b}\bar{b}$ tetraquarks we obtain bound states below the respective $BB^*$ and $B_sB^*$ thresholds, which we compare to other Lattice QCD determinations. For the b-quark cousins of the $D_{s0}^*(2317)$ and $D_{s1}(2460)$ we obtain predictions with a better precision and better controlled systematic uncertainty than previous lattice QCD calculations. Overall our uncertainties are dominated by systematics and we outline future steps to remedy this.
