Volume 525 - Fourth Italian Workshop on Physics at High Intensity (WIFAI2025) - Session: Young Scientific Forum
The X(3872) puzzle: insights from its radiative decays
D. Germani
Full text: pdf
Published on: July 20, 2026
Abstract
The internal structure of the $X(3872)$ is still a highly debated topic in heavy-quarkonium physics. Here, we investigate its radiative transitions, specifically $X(3872)\to J/\psi\,\gamma$ and $X(3872)\to \psi^\prime\gamma$, assuming a compact tetraquark configuration. The decay amplitudes are evaluated within a non-relativistic approach, relying on the initial tetraquark wave function. To model this state, we apply the Born--Oppenheimer approximation, separating the dynamics of the slow heavy charm quarks from the fast light quarks. By variationally determining the effective Born--Oppenheimer potential, we solve the Schr\"odinger equation for the $c\bar c$ subsystem. Our theoretical prediction for the ratio of the radiative branching fractions is $\mathcal{R}_{\mathrm{th}} = 1.4 \pm 0.3$, which nicely matches recent LHCb data. More broadly, this technique successfully maps out the mass spectrum of compact $c\bar c q\bar q$ configurations, demonstrating the effectiveness of the Born--Oppenheimer method for exploring exotic hadron structures.
DOI: https://doi.org/10.22323/1.525.0052
How to cite

Metadata are provided both in article format (very similar to INSPIRE) as this helps creating very compact bibliographies which can be beneficial to authors and readers, and in proceeding format which is more detailed and complete.

Open Access
Creative Commons LicenseCopyright owned by the author(s) under the term of the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.