2026/07/30 by Shuai Yin, Ti Gong, Jingya Zhu
Physics and Astronomy · #hep-ph
10 pages, 5 figures, 3 tables
arxiv created 2026/07/30 · arxiv updated 2026/07/31
Motivated by recent experimental observations, we investigate the JP distribution of low-energy compact tetraquark states using symmetry analysis based on inherent nodal structures. Assuming tetrahedral and square configurations for the qq q q system, we derive the allowed orbital structures from the restricted representations of S4 onto S2× S2 for L≤3. The resulting accessible-state distribution indicates that low-energy compact tetraquark states predominantly favor JP=2+. We further find that the symmetry-driven distribution is qualitatively similar to that of the three-flavor four-quark system, and that the dominant JP=2+ pattern persists after including chromomagnetic interaction (CMI) effects. These results suggest that the low-lying compact tetraquark spectrum is primarily constrained by symmetry, while dynamics mainly affect the detailed state distribution. Applying this framework to the fully charmed candidates X(6600), X(6900), and X(7100), we find that their observed JPC=2++ quantum numbers are consistent with a low-lying compact tetraquark interpretation. Additional dynamical mechanisms beyond CMI may be needed to explain the detailed energy ordering of fully charmed tetraquark states.