The electromagnetic multipole moments of the charged open-flavor $Z_{\bar cq}$ states

TL;DR

This study calculates the electromagnetic multipole moments of open-flavor $Z_{ar cq}$ states using light-cone QCD sum rules, providing insights into their internal structure and potential experimental measurements.

Contribution

It introduces a diquark-antidiquark model to compute magnetic and quadrupole moments of $Z_{ar cq}$ states, a novel application in this context.

Findings

Magnetic moments are large and measurable in future experiments.

Quadrupole moments are very small, indicating nonspherical charge distribution.

Results offer valuable information on the internal structure of $Z_{ar cq}$ states.

Abstract

The electromagnetic multipole moments of the open-flavor $Z_{\bar cq}$ states are investigated by assuming a diquark-antidiquark picture for their internal structure and quantum numbers $J^{PC} = 1^{+-}$ for their spin-parity. In particular, their magnetic and quadrupole moments are extracted in the framework of light-cone QCD sum rule by the help of the photon distribution amplitudes. The electromagnetic multipole moments of the open-flavor $Z_{\bar cq}$ states are important dynamical observables, which encode valuable information on their underlying structure. The results obtained for the magnetic moments of different structures are considerably large and can be measured in future experiments. We obtain very small values for the quadrupole moments of $Z_{\bar cq}$ states indicating a nonspherical charge distribution.