Novel coupled channel framework connecting quark model and lattice QCD: an investigation on near-threshold $D_s$ states

Abstract

A novel framework is proposed to extract near-threshold resonant states from finite-volume energy levels of lattice QCD and is applied to elucidate structures of the positive parity $D_s$. The quark model, the quark-pair-creation mechanism and $D^{(\ast )}K$ interaction are incorporated into the Hamiltonian effective field theory. The bare $1^{+}$ $c\bar{s}$ states are almost purely given by the states with heavy-quark spin bases. The physical $D_{s0}^{\ast }(2317)$ and $D_{s1}^{\ast }(2460)$ are the mixtures of bare $c\bar{s}$ core and $D^{(\ast )}K$ component, while the $D_{s1}^{\ast }(2536)$ and $D_{s2}^{\ast }(2573)$ are almost dominated by bare $c\bar{s}$. Furthermore, our model reproduces the clear level crossing of the $D_{s1}^{\ast }(2536)$ with the scattering state at a finite volume.

7 pages, 3 figures; accepted for publication in Physical Review Letters