${\gamma }^{\ast }N\to {\Delta }^{+}(1600)$ transition form factors in light-cone sum rules

Abstract

The form factors of ${\gamma }^{\ast }N\to \Delta (1600)$ transition is calculated within the light-cone sum rules assuming that ${\Delta }^{+}(1600)$ is the first radial excitation of $\Delta (1232)$. The $Q^2$ dependence of the magnetic dipole ${\tilde{G}}_M(Q^2)$, electric quadrupole ${\tilde{G}}_E(Q^2)$, and Coulomb quadrupole ${\tilde{G}}_c(Q^2)$ form factors are investigated. Moreover, the $Q^2$ dependence of the ratios $R_{EM}=-\frac{{\tilde{G}}_E(Q^2)}{{\tilde{G}}_M{Q}^2}$ and $R_{SM}=-\frac{1}{4m_{\Delta (1600)}^2}\sqrt{4m_{\Delta (1600)}^2{Q}^2+(m_{\Delta (1600)}^2-Q^2-m_N^2{)}^2}\frac{{\tilde{G}}_c(Q^2)}{{\tilde{G}}_M(Q^2)}$ are studied. Finally, our predictions on ${\tilde{G}}_M(Q^2)$, ${\tilde{G}}_E(Q^2)$, and ${\tilde{G}}_C(Q^2)$ are compared with the results of other theoretical approaches.

19 pages, 5 figures