Charmless decays of the spin-2 partner of X(3872)

• Published in: The European physical journal. C, Particles and fields Particles and fields, 2024-10, Vol.84 (10), p.1019-11, Article 1019
• Main Authors: Cai, Zu-Xin, Jia, Zhao-Sai, Li, Gang, Liu, Shi-Dong, Xie, Ju-Jun
• Format: Article
• Language: English
• Subjects: Astronomy; Astrophysics and Cosmology; Collaboration; Constituents; Decay; Elementary Particles; Hadrons; Heavy Ions; Measurement Science and Instrumentation; Mesons; Nuclear Energy; Nuclear Physics; Physics; Physics and Astronomy; Quantum Field Theories; Quantum Field Theory; Regular Article - Theoretical Physics; String Theory; Symmetry; Theoretical physics
• ISSN: 1434-6052; 1434-6044; 1434-6052
• DOI: 10.1140/epjc/s10052-024-13424-y

The Belle collaboration recently reported a pro-mising candidate for the spin-2 D ∗ D ¯ ∗ partner of the X (3872), called the X 2 for short, having a mass of ( 4014.3 ± 4.0 ± 1.5 ) MeV and a width of ( 4 ± 11 ± 6 ) MeV . In present work, we assume the X 2 as a pure molecule of the D ∗ D ¯ ∗ under four cases, i.e., pure neutral components ( θ = 0 ), isospin singlet ( θ = π / 4 ), neutral components dominant ( θ = π / 6 ), and purely charged components ( θ = π / 2 ), where θ is a phase angle describing the proportion of neutral and charged constituents. Using an effective Lagrangian approach, we calculated the partial widths of X 2 → V V and X 2 → P P ( V and P stand for light vector and pseudoscalar mesons, respectively). The predicted decay widths of X 2 → V V can reach a few hundreds of keV , while the decay widths of X 2 → P P are about several tens of keV . In addition, the effects from the proportion of neutral and charged constituent on the decay widths of X 2 → V V and PP are also investigated. We hope that the present calculations will be checked experimentally in the future.