Contribution of $DK$ Continuum in the QCD Sum Rule for $D_{sJ}(2317)$

Abstract

Using the soft-pion theorem and the assumption on the final-state interactions, we include the contribution of $DK$ continuum into the QCD sum rules for $D_{sJ}(2317)$ meson. We find that this contribution can significantly lower the mass and the decay constant of $D_s(0^{+})$ state. For the value of the current quark mass $m_c(m_c)=1.286\mathrm{GeV}$, we obtain the mass of $D_s(0^{+})$ $M=2.33\pm 0.02\mathrm{GeV}$ in the interval $s_0=7.5-8.0{\mathrm{GeV}}^2$, being in agreement with the experimental data, and the vector current decay constant of $D_s(0^{+})$ $f_0=0.128\pm 0.013\mathrm{GeV}$, much lower than those obtained in previous literature.