Tetraquark interpolating fields in a lattice QCD investigation of the Ds0*(2317) meson

We investigate the D-s0* (2317) meson using lattice QCD and considering correlation functions of several (c) over bars two-quark and (c) over bars((u) over baru + (d) over bard) four-quark interpolating fields. These interpolating fields generate different structures in color, spin and position space including quark-antiquark pairs, tetraquarks and two-meson scattering states. For our computation we use an ensemble simulated with pion mass m(pi) approximate to 0.296 GeV and spatial volume of extent 2.90 fm. We find in addition to the expected spectrum of two-meson scattering states another state around 60 MeV below the DK threshold, which we interpret as the D-s0* (2317) meson. This state couples predominantly to a quark-antiquark interpolating field and only weakly to a DK twomeson interpolating field. The coupling to the tetraquark interpolating fields is essentially 0, rendering a tetraquark interpretation of the D-s0*(2317) meson rather unlikely. Moreover, we perform a scattering analysis using Ltischer's method and the effective range approximation to determine the D-s0*(2317) mass for infmite spatial volume. We find this mass 51 MeV below the DK threshold, rather close to both our finite volume result and the experimentally observed value.