Systematic exploration of triply heavy tetraquarks: spectroscopic and decay characteristics

While hidden, singly, doubly, and fully heavy tetraquark states have been experimentally observed, triply heavy tetraquark states remain unconfirmed. We systematically investigate the spectroscopic and decay properties of four triply heavy-flavor tetraquark systems ($cc\bar{c}\bar{n}$, $cc\bar{c}\bar{s}$, $bb\bar{b}\bar{n}$, $bb\bar{b}\bar{s}$; $n=u,d$) based on the nonrelativistic quark model. Using an effective Hamiltonian, we employ the Gaussian expansion method to solve the four-body Schrödinger equation and incorporate the effect of color-spin configuration mixing. Results show both $cc\bar{c}\bar{q}$ and $bb\bar{b}\bar{q}$ systems have two $J^P=0^{+}$, three $J^P=1^{+}$, and one $J^P=2^{+}$ states, with ground-state masses of 5.2-5.5 GeV and 15.0-15.3 GeV, respectively. Root-mean-square radius analysis supports compact tetraquark configurations. All states are unstable, with rearrangement strong decays dominant and negligible radiative decays. Narrow resonances (e.g., $T_{c^2\bar{c}\bar{s}}(5360,0^{+})$, $T_{b^2\bar{b}\bar{n}}(15052,0^{+})$) arise from Feynman amplitude cancellation. We propose experimental searches in $J\mathrm{/}\psi D_s^{\ast }$/ ${\eta }_c{D}_s$ (5.3-5.4 GeV) and $\mathrm{{\rm Y}}{B}^{\ast }$ (15.0-15.1 GeV) channels, providing key guidance for triply heavy tetraquark identification.