Pole structure and compositeness of Tbb̅1(10650)+ via the uniformized S-matrix

Abstract

We probe the T_bb̅1(10650)⁺ resonance state by employing the uniformized S-matrix to demonstrate that the exotic meson can be characterized by multiple distinct pole structures, each leading to fundamentally different physical interpretations. Through residue analysis and the Weinberg compositeness criterion, we investigated the internal structure of the hadronic resonance for a given pole structure. Our results reveal that both an isolated pole on the [bb] sheet and a pole-shadow pair in the [bb] and [tb] sheets can effectively mimic the line shape of the empirical data for the T_bb̅1(10650)⁺ state. The isolated pole configuration hints a predominantly molecular nature, while the pole-shadow pair configuration points to a predominantly compact tetraquark state.