Investigating Fully Strange Tetraquark System with Positive Parity in a Chiral Quark Model

Abstract

Motivated by the intriguing discovery of X(6900) by the LHCb collaboration, we undertake a comprehensive study of the ss¯ss¯ tetraquark system with positive parity, employing the Gaussian expansion within the chiral quark model method. We consider two structures, the diquark–antidiquark (ss-s¯s¯) structure and meson–meson (ss¯-ss¯) structure, covering all conceivable color and spin configurations. Despite the absence of bound states in our calculations, we have identified potential resonant states with JP=0+, namely, R(0,2150) and R(0,2915), as well as a resonant state with JP=1+, denoted as R(1,2950), and a resonant state with JP=2+, denoted as R(2,2850), utilizing the real-scaling method. By comparing their energies and widths, we suggest that R(0,2915) and R(1,2950) may share characteristics with X(6900), while R(0,2150) could be a promising candidate for the experimental state f0(2100). We strongly advocate for experimental investigations to shed light on the existence and properties of these resonant states.

Keywords

• quark model
• resonance
• tetraquark