Magnetic moment of the pentaquark ${\mathrm{\Theta }}^{+}(1540)$ as diquark-diquark-antiquark state with QCD sum rules

In this article, we study the magnetic moment of the pentaquark state ${\mathrm{\Theta }}^{+}(1540)$ as diquark-diquark-antiquark ($[ud][ud]\bar{s}$) state with the QCD sum rules in the external weak electromagnetic field (EFSR) and the light-cone QCD sum rules (LCSR) respectively. The numerical results indicate the magnetic moment is about ${\mu }_{{\mathrm{\Theta }}^{+}}=-(0.11\pm 0.02){\mu }_N$ for the EFSR and ${\mu }_{{\mathrm{\Theta }}^{+}}\approx -(0.1-0.5){\mu }_N$ for the LCSR. As the values obtained from the EFSR are more stable than the corresponding ones from the LCSR, ${\mu }_{{\mathrm{\Theta }}^{+}}=-(0.11\pm 0.02){\mu }_N$ is more reliable.