Fine Structure and Decays of Hidden-Strangeness Tetraquarks in the Dynamical Diquark Model

Abstract

We analyze the fine structure and ``fall-apart'' decay patterns of hidden-strangeness tetraquarks within the dynamical diquark model. Several well-established negative-parity resonances listed by the Particle Data Group (PDG) [$φ(2170)$, $η(2225)$, $η(2370)$] are examined as potential $q\bar q s\bar s$ tetraquark candidates using a Hamiltonian that incorporates (iso)spin-dependent, spin--orbit, and tensor interactions. We further show that the isovector resonances $ρ(2150)$ and $ρ_3(2250)$ observed by BESIII in $ψ(2S)\rightarrow K^{+}K^{-}η$ are compatible with a tetraquark assignment. Predictions for 28 states, including those with exotic quantum numbers, are also presented. Comparison of the model spectrum with the PDG's unverified ``Further States'' highlights additional promising candidates worth future experimental investigation. The predicted fall-apart decay channels are easily reconstructed by experiment, and may stimulate ongoing searches for hidden-strangeness tetraquarks at GlueX and BESIII.

Figures (2)

• Figure 1: List of negative-parity resonances tabulated by the PDG ParticleDataGroup:2024cfk with mass above 2.1 GeV (and below $m_{\eta_c} = 2.984$ GeV). Masses and total decay widths of $\rho(2150)$ and $\rho_3(2250)$ are taken from BESIII measurements in the channel $\psi(2S)\rightarrow K^{+}K^{-}\eta$BESIII:2019dme.
• Figure 2: Predicted spectrum of the $P$-wave hidden-strangeness tetraquarks comprising the $\Sigma^+_g(1P)$ multiplet of the dynamical diquark model. Blue (circle) and red (square) points denote $I=0$ ($I=1)$ states, respectively. States used as fit inputs are labeled.