# Radiative open charm decay of the Y(3940), Z(3930), X(4160) resonances

## TL;DR

This paper calculates the radiative decay amplitudes of certain charmonium-like states, revealing distinctive mass distribution features that can help identify their underlying structure through experimental measurements.

## Contribution

It provides the first detailed theoretical predictions of radiative decay amplitudes for X, Y, Z charmonium-like resonances and related states, highlighting their D* D* nature.

## Key findings

- Mass distributions show peculiar behavior linked to D* D* structure.
- Predictions can guide experimental identification of these states.
- Results support the molecular interpretation of the resonances.

## Abstract

We determine the radiative decay amplitudes for decay into $D^*$ and $\bar{D} \gamma$, or $D^*_s$ and $\bar{D}_s \gamma$ of some of the charmonium like states classified as X,Y,Z resonances, plus some other hidden charm states which are dynamically generated from the interaction of vector mesons with charm. The mass distributions as a function of the $\bar{D} \gamma$ or $\bar{D}_s \gamma$ invariant mass show a peculiar behavior as a consequence of the $D^* \bar{D}^*$ nature of these states. The experimental search of these magnitudes can shed light on the nature of these states.