The experimental observation of $a_0(1710)$: Long awaited from Regge approach

Abstract

Recently, the BABAR (in 2021), BESIII (in 2022), and LHCb (in 2023) Collaborations reported the observation of the $a_0(1710)$ resonance. This has sparked a lively debate in the literature about the nature of this possible isospin partner of $f_0(1710)$, since the latter has long been regarded as the main candidate for the lightest glueball. We highlight the clear prediction of $a_0(1710)$ in 2007 within the Regge approach using the observed hydrogen-like degeneracy in the spectrum of light mesons. Our reanalysis of the data used shows that the prediction was reliable and thus indicates that $a_0(1710)$ and $f_0(1710)$ are conventional quark-antiquark states.