The nature of the φ(2170) meson, a candidate for an excited strangeonium, remains an enigma in particle physics. Recent observations of $e^+e^-$ collisions producing $φη$ and $φη'$ meson pairs have revealed an anomaly: the φ(2170) appears prominently in the $φη'$ channel but not in $φη$, despite the $φη'$ decay being strongly suppressed by phase space. This unexpected behavior suggests that current models for the φ(2170) are incomplete or that additional physical phenomena are at play.

A new analysis proposes that this disproportion in decay channels can be explained by the dynamics of strange-meson loops. Researchers compared two mechanisms: short-distance quark-pair creation and long-distance transitions mediated by strange-meson loops. The first mechanism underestimates the observed $φη'/φη$ strength ratio. However, strange-meson loops, which involve the formation and annihilation of $K^{(*)}K^{(*)}η^{(\prime)}$ meson pairs, naturally enhance the decay to $φη'$ relative to $φη$. This is due to an SU(3)-flavor factor at the $K^{(*)}K^{(*)}η^{(\prime)}$ vertex that suppresses the transition to $φη$.

The inclusion of these strange-meson loops has allowed for a consistent description of the cross sections for both decay channels. This result highlights the importance of long-distance dynamics in the decays of excited strangeonia with hidden strangeness. Furthermore, high-precision data for the $φη$ channel suggest the possible existence of an additional narrow vector state near 2.15 GeV, with a width of approximately 25 MeV. If confirmed, this would be a promising exotic-hadron candidate in the light-vector sector.