ϒ(5S) in the unquenched quark model

The observation of the Formula: see text state by Belle II Collaboration has sparked significant interest in the theoretical understanding of such states within the context of hadron physics. Considering the similar mass and the decay with, as well as the same quantum numbers Formula: see text with the Formula: see text state, which is referred to be the Formula: see text in PDG, in this work, we try to calculate the mass of the Formula: see text state. The model used to predict the high-energy spectrum of these states generally involves a constituent quark model, which can describe a variety of properties of hadrons containing heavy quarks. In the framework of the unquenched quark model, a coupled-channel calculation is employed to explore the effect of open-bottom meson–meson thresholds on the Formula: see text state. The hypothesis is that coupled-channel effects could be large enough to create new dynamically generated states, thus potentially explaining the nature of the Formula: see text state, as well as whether Formula: see text and Formula: see text is the same state. The results indicate that unquenched effects play a crucial role in explaining Formula: see text state, providing a plausible mechanism for its formation. Besides in our calculations, Formula: see text and Formula: see text may be two different states.