An Effective Theory approach to $\bar{B}_s$ mesons involving $SU(3)$ heavy meson symmetry and constituent quark-model states

Abstract

The bottom partners of the $D^\ast_{s0}(2317)$ and $D_{s1}(2460)$ have not been measured yet but the existence of these bottom-strange $J^P=0^+$ and $J^P=1^+$ states is motivated by heavy quark flavor symmetry and heavy quark spin symmetry. Here we show the predictions for such heavy quark partners using a unitarized effective approach involving $SU(3)$ chiral heavy meson symmetry and incorporating explicit di-quark Fock components ($Q\bar{q}$) to the theory in a heavy quark spin and flavour symmetry consistent way. We take advantage of the energy levels spectrum for $0^+$ and $1^+$ $\bar{B}_s$ mesons obtained in a recent lattice QCD simulation to constrain the coupling of the $Q\bar{q}$ components. By fitting the lattice QCD energy levels with the energy levels obtained with the model in finite volume, we are able to make predictions for these exotic $\bar{B}_s$ mesons. Our predictions are compatible with the lattice QCD results and previous heavy meson chiral perturbation theory predictions.