Recent spectroscopy highlights from COMPASS

The COMPASS experiment took data at the M2 beam line at CERN with a rich hadron physics program for the last two decades. This talk focuses on the spectroscopy program, where a 190 GeV negatively charged hadron beam was shot on a fixed proton target. We investigate diffractive dissociation events in various final states using both the π⁻ and K⁻ component of the beam. Performing a partial-wave decomposition and fitting the result with resonance models allows us to measure aJ,πJ,KJ and K^*J states and to extract their resonance parameters. Especially exciting are exotic mesonic states beyond the qq̄ systematics of up, down and strange quarks. An example is a hybrid state where gluonic degrees of freedom contribute to the quantum numbers. Phenomenological models as well as recent lattice QCD simulations predict the lightest hybrid state to have spin-exotic quantum numbers JPC=1⁻⁺. A coupled-channel fit to the COMPASS data using the selected ηπ and η^π final states results in 1⁻⁺ signals at different masses originating from a single pole at about 1.6 GeV/c². In addition, we show the recently released results for the ωπ⁻π⁰ final state, confirming the π₁(1600) state, as well as several other known states. The strange-light sector is probed with the reaction K⁻ p → K⁻π⁻π⁺p, where COMPASS collected the largest data set to date and we show results for known states as well as new states, e.g. an exotic 0⁻ candidate. Supported by BMBF.