Fully strange tetraquark resonant states as the cousins of X(6900)

Abstract

We conduct systematic calculations of the S-wave fully strange systems with “normal” (JPC=0++,1+−,2++) and “exotic” (JPC=0+−,1++,2+−) C-parities, which are the strange analog of the fully charmed tetraquark state X(6900). Within a constituent quark potential model, we employ the Gaussian expansion method to solve the four-body Schrödinger equation and the complex scaling method to identify resonant states. We obtain a series of resonant states and zero-width states in the mass range of 2.7 to 3.3 GeV, with their widths ranging from less than 1 to about 50 MeV. Their rms radii strongly indicate that they are compact tetraquark states. Among these states, the T4s,2++(2714) may be the most likely one to be observed experimentally. We urge the experimental exploration of the 2++ sss¯s¯ state around 2.7 GeV in the ϕϕ channel. Since the lowest S-wave sss¯s¯ state is around 2.7 GeV, the compact wave sss¯s¯ states are expected to be heavier. Hence, ϕ(2170) and X(2370) are unlikely to be compact tetraquark states. Published by the American Physical Society 2024