Electromagnetic properties of the $\Sigma_{c}(2800)^+$ and $\Lambda_c(2940)^+$ states via light-cone QCD

TL;DR

This paper calculates the electromagnetic properties of the $\Sigma_{c}(2800)^+$ and $\Lambda_c(2940)^+$ states using light-cone QCD sum rules, aiming to understand their internal quark-gluon structure and guide future experiments.

Contribution

It provides the first theoretical estimates of magnetic dipole, electric quadrupole, and magnetic octupole moments for these states assuming a molecular structure.

Findings

Magnetic dipole moments: $\mu_{\Sigma_c^{+}}=0.26 \pm 0.05~\mu_N$, $\mu_{\Lambda_c^{+}}=-0.31 \pm 0.04~\mu_N$

Electric quadrupole and magnetic octupole moments indicate non-spherical charge distribution

Results can aid future experimental searches and structural understanding of these states.

Abstract

The $\Sigma_{c}(2800)^+$ and $\Lambda_c(2940)^+$ states are among the most interesting and intriguing particles whose internal structures have not yet been elucidated. Inspired by this, the magnetic dipole moments of the $\Sigma_{c}(2800)^+$ and $\Lambda_c(2940)^+$ states with quantum numbers $J^P = \frac{1}{2}^-$ and $J^P = \frac{3}{2}^-$, respectively, are analyzed in the framework of QCD light-cone sum rules, assuming that they have a molecule composed of a nucleon and a $D^{(*)}$ meson. The magnetic dipole moments are obtained as $\mu_{\Sigma_c^{+}}=0.26 \pm 0.05~\mu_N$ and $\mu_{\Lambda_c^{+}}=-0.31 \pm 0.04~\mu_N$. The magnetic dipole moment is the leading-order response of a bound system to a weak external magnetic field. It therefore offers an excellent platform to explore the inner organization of hadrons governed by the quark-gluon dynamics of QCD. Comparison of the findings of this analysis with future experimental results on the magnetic dipole moments of the $\Sigma_{c}(2800)^+$ and $\Lambda_c(2940)^+$ states may shed light on the nature and internal organization of these states. The electric quadrupole and magnetic octupole moments of the $\Lambda_c(2940)^+$ states have also been calculated, and these values are determined to be $\mathcal Q_{\Lambda_c^+} = (0.65 \pm 0.25) \times 10^{-3}$~fm$^2$ and $ \mathcal O_{\Lambda_c^+} = -(0.38 \pm 0.10) \times 10^{-3}$~fm$^3$, respectively. The values of the electric quadrupole and magnetic octupole moments show a non-spherical charge distribution. We hope that our estimates of the electromagnetic properties of the $\Sigma_{c}(2800)^+$ and $\Lambda_c(2940)^+$ states, together with the results of other theoretical studies of the spectroscopic parameters of these states, will be useful for their search in future experiments and will help us to define the exact internal structures of these states.