Eur. Phys. J. C (2025) 85: 389
https://doi.org/10.1140/epjc/s10052-025-14111-2

Letter

New insights into the doubly charmed exotic mesons

¹ School of Physics and Electronics, Hunan University, 410082, Changsha, China
² Hunan Provincial Key Laboratory of High-Energy Scale Physics and Applications, Hunan University, 410082, Changsha, China
³ Department of Physics, Tianjin Renai College, 301636, Tianjin, China
⁴ Center for Exploration of Energy and Matter, Indiana University, 47403, Bloomington, IN, USA
⁵ Physics Department, Indiana University, 47405, Bloomington, IN, USA
⁶ Thomas Jefferson National Accelerator Facility, 23606, Newport News, VA, USA

^a dailingyun@hnu.edu.cn

Received: 25 December 2024
Accepted: 21 March 2025
Published online: 5 April 2025

Abstract

Using effective Lagrangians constrained by the heavy quark spin symmetry and chiral symmetry, for the light quarks, we analyze the $D^0{D}^0{\pi }^{+},$${\overline{D}}^0{D}^0{\pi }^0$ and $D^0{\overline{D}}^{\ast 0}$ invariant mass spectra. Performing a simultaneous analysis of the doubly charmed and charm-anti-charm states gives further insights into the nature of the $T_{\mathit{cc}}^{+}$ and ${\chi }_{c1}^0(3872),$ exotic hadrons. It is confirmed that both states should lie below their respective $D{D}^{\ast }$/$D{\overline{D}}^{\ast }$ thresholds. Also, the contributions of the triangle and box diagrams are negligible.