Spectrum of $[cq][ar{s}ar{q}]$ tetraquarks: Nature of $D^*_{s0}(2317)$, $D_{s1}(2460)$ and $T^*_{car s0}(2900)$

Motivated by the recent observations of exotic open-charm tetraquark candidates (T^a_{c\bar{s}0}(2900)^{++}) and (T^a_{c\bar{s}0}(2900)^{0}), we systematically calculate the mass spectra of ([cq][\bar{s}\bar{q}]) tetraquarks within a nonrelativistic constituent quark potential model. In the model, the tetraquark states are treated as diquark-antidiquark bound systems with an interior interaction similar to the quark-antiquark interaction in conventional mesons. The well established states (D_{s0}^*(2317)) with (J^P=0^+) and (D_{s1}(2460)) with (J^P=1^+) could be identified as the two ground states of the ([cq][\bar{s}\bar{q}]) system. (T^a_{c\bar{s}0}(2900)^{0}) and (T^a_{c\bar{s}0}(2900)^{++}) could be naturally interpreted as radially excited (0^+) tetraquark states with different interior components. Their large mass difference may result from their different interior structure instead of an isospin symmetry breaking. Whether (T^a_{c\bar{s}0}(2900)^{0}) and (T^a_{c\bar{s}0}(2900)^{++}) belong to an isospin triplet deserves further experimental investigation. In addition, there may be another (0^+) ([cq][\bar{s}\bar{q}]) tetraquark state with mass around $2450$ MeV, which is composed of a $cq$ diquark and a $\bar s\bar q$ antidiquark both with spin-0. In the energy region $2640-2700$ MeV, there may be a $J^P=2^+$ ([cq][\bar{s}\bar{q}]) tetraquark state composed of the $cq$ diquark and the $\bar s\bar q$ antidiquark both with spin-1.

💡 Research Summary

The authors investigate the spectrum of open‑charm tetraquarks of the type (