Magnetic moment of the pentaquark state ${\Theta }^{+}(1540)$

Abstract

In this article, we study the magnetic moment of the pentaquark ${\Theta }^{+}(1540)$ as (scalar)diquark-(pseudoscalar)diquark-antiquark state with the QCD sum rules approach in the external electromagnetic field. Due to the special structure of the interpolating current, only the electromagnetic interactions of the $s$ quark with the external field have contributions to the magnetic moment with tensor structure $\{{\sigma }_{\mu \nu }\hat{p}+\hat{p}{\sigma }_{\mu \nu }\}$. The numerical results indicate the magnetic moment of the pentaquark state ${\Theta }^{+}(1540)$ is about ${\mu }_{{\Theta }^{+}}=(0.16\pm 0.03){\mu }_N$.

Comments: 10 pages, 1 figure, input parameters changed, add discussions