The $Y(4260)$ and $Y(4360)$ enhancements within coupled-channels

TL;DR

This paper investigates the mysterious $Y(4260)$ and $Y(4360)$ structures in charmonium energy regions, proposing a coupled-channels model with mesonic loops and charmonium vectors to explain their formation.

Contribution

It introduces a unitarized effective Lagrangian model that combines mesonic loops and charmonium vectors to generate the observed enhancements and pole structures.

Findings

Reproduces the line-shapes of $Y(4260)$ and $Y(4360)$

Identifies poles associated with the observed structures

Highlights the importance of coupled-channels effects in charmonium

Abstract

Puzzling structures have been observed in the charmonium energy region, namely the $Y(4260)$ and the $Y(4360)$, that cannot be easily accommodated within quark model frameworks. The proximity of nearby dominant hadronic thresholds suggests that they play an important role in the formation of the enhancements. We present results of an unitarized effective Lagrangian model, where mesonic loops, equivalent to coupled-channels, and charmonium vectors $\psi$ interplay to generate line-shapes and poles.