Decay width of the pentaquark state ${\Theta }^{+}(1540)$ with QCD sum rules

Abstract

In this article, we take the point of view that the pentaquark state ${\Theta }^{+}(1540)$ has negative parity, and choose the diquark-triquark type interpolating current to calculate the strong coupling constant $g_{\Theta NK}$ in the QCD sum rule approach. Our numerical results indicate the values of the strong coupling constant $g_{\Theta NK}$ are very small, $|g_{\Theta NK}|=0.175\pm 0.084$, and the width ${\Gamma }_{\Theta }<4MeV$, which can explain the narrow width $\Gamma \le 10MeV$ naturally.

Comments: 10 pages, 2 figures, Third version, to appear in Phys.Rev.D