Speaker
Description
Quark confinement in hadrons is a well-established phenomenon. However, a complete quantitative understanding of the principles governing the quark configurations realized in nature remains elusive. Such an understanding is crucial in the context of ongoing searches for physics beyond the Standard Model in decays to multi-body hadronic final states. To address this, we study the excitation spectra of light mesons, including searches for exotic states that defy the rules of the traditional quark model.
We discuss measurements of the non-strange and strange light-meson spectrum at the COMPASS experiment. A comprehensive partial-wave analysis of the $K^-\pi^-\pi^+$ final state yields a broad spectrum of strange mesons and identifies the first candidate for an exotic strange-meson signal with $J^P=0^-$.
Furthermore, we present studies from the Belle II experiment. We report on experimental challenges in charged particle identification and discuss a search for $C\!P$ violation in $B \to K\pi\pi$ decays utilizing amplitude analyses. Finally, we present ongoing efforts to study light mesons in multi-body hadronic $\tau$-lepton decays and the prospects for measuring the spin quantum state of $\tau$ pairs produced in the $e^+e^-$ collisions.