Prediction of new $T_{cc}$ states of $D^{*} D^{*}$ and $D^{*}_s D^{*}$ molecular nature

TL;DR

This paper predicts new molecular $T_{cc}$-like states in the $D^* D^*$ and $D^*_s D^*$ systems using a theoretical framework, identifying potential bound states and threshold effects.

Contribution

It extends the molecular state model of $T_{cc}$ to predict new bound states in related systems with minimal parameter adjustments.

Findings

Bound states with MeV-scale binding energies in $D^*D^*$ system.

Strong cusp observed around threshold in $D^*_s D^*$ system.

Bound states only in the $J^P=1^+$ channel.

Abstract

We extend the theoretical framework used of describe the $T_{cc}$ state as a molecular state of $D^* D$ and make predictions for the $D^*D^*$ and $D^*_s D^*$ systems, finding that they lead to bound states only in the $J^P=1^+$ channel. Using input needed to describe the $T_{cc}$ state, basically one parameter to regularize the loops of the Bethe-Salpeter equation, we find bound states with bindings of the order of the MeV and similar widths for $D^*D^*$ system, while the $D^{*}_s D^{*}$ system develops a strong cusp around threshold.