Fully open-flavor tetraquark states $$bc\bar{q}\bar{s}$$ and $$sc\bar{q}\bar{b}$$ with $$J^{P}=0^{+},1^{+}$$

AbstractWe have studied the masses for fully open-flavor tetraquark states $$bc\bar{q}\bar{s}$$bcq¯s¯ and $$sc\bar{q}\bar{b}$$scq¯b¯ ($$q=u, d$$q=u,d) with quantum numbers $$J^{P}=0^{+},1^{+}$$JP=0+,1+. We systematically construct all diquark–antiquark interpolating currents and calculate the two-point correlation functions and spectral densities in the framework of QCD sum rule method. Our calculations show that the masses are about $$7.1-7.2$$7.1-7.2 GeV for the $$bc\bar{q}\bar{s}$$bcq¯s¯ tetraquark states and $$7.0-7.1$$7.0-7.1 GeV for the $$sc\bar{q}\bar{b}$$scq¯b¯ tetraquarks. The masses of $$bc\bar{q}\bar{s}$$bcq¯s¯ tetraquarks are below the thresholds of $$\bar{B}_{s}D$$B¯sD and $$\bar{B}_{s}^{*}D$$B¯s∗D final states for the scalar and axial-vector channels respectively. The $$sc\bar{q}\bar{b}$$scq¯b¯ tetraquark states with $$J^{P}=1^{+}$$JP=1+ lie below the $$B_{c}^{+}K^{*}$$Bc+K∗ and $$B_{s}^{*}D$$Bs∗D thresholds. Such low masses for these possible tetraquark states indicate that they can only decay via weak interaction and thus are very narrow and stable.