Freed-Isobar Partial-Wave Analysis of the 𝜔𝜋𝜋 Final State at COMPASS

by Philipp Haas

Thursday 24 Jul 2025, 09:30 → 10:30 Europe/Berlin

E18/ENE Seminar Room 3268 (TUM PH)

The COMPASS experiment was a fixed-target experiment at the CERN SPS. Part of its physics program was the study of the non-strange light-meson spectrum. A particular interesting final state is $\omega(782)\pi^-\pi^0$. Aside from measuring $a$ and $\pi$ mesons using a conventional partial-wave analysis (PWA), the application of the freed-isobar PWA — a technique developed at E18 for the $\pi^-\pi^-\pi^+$ final state — to $\omega(782)\pi^-\pi^0$ allows the study of $\rho$ and $b$ mesons. In this talk we discuss first results of freed-isobar analyses of $\omega(782)\pi^-\pi^0$ with a focus on measuring the resonance parameters of the $b_1(1235)$ meson.