Employing Approximate Symmetries for Hidden Pole Extraction

Recent lattice analyses of the $D\pi$ scattering by Hadron Spectrum Collaboration(HadSpec) report only one pole in the $D_0^{\ast }$ channel. This is in odds with the unitarised chiral perturbation theory analyses, which predict the $D_0^{\ast }(2300)$ as the interplay of two poles. We provide an explanation for this contradiction $-$ the exsistence of a hidden pole. We further show that the hidden pole can be better extracted from the lattice data by imposing SU(3) flavour constraints on the fitting amplitudes.