Measurement of the presence of $a_1(1420)$ and $\omega(782)$ in $\tau^{-}\to \pi^{-}\pi^{+}\pi^{-}\nu_{\tau}$ at Belle

• Published in: SciPost physics proceedings no. 17; p. 008
• Main Authors: Rabusov, Andrei, Greenwald, Daniel, Paul, Stephan
• Format: Journal Article
• Language: English
• Published: SciPost 23.07.2025
• ISSN: 2666-4003; 2666-4003
• DOI: 10.21468/SciPostPhysProc.17.008

We present preliminary results of a partial-wave analysis of \tau^-\to\pi^-\pi^-\pi^+\nu_\tau τ − → π − π − π + ν τ using data from the Belle experiment at the KEKB \mathrm{e}^+\mathrm{e}^- e + e − collider. We validate our model with a model-independent analysis. We see the \mathrm{a}_1(1420) a 1 ( 1420 ) and a G-parity-violating 1^-[\omega(782)\pi]_\mathrm{P} 1 − [ ω ( 782 ) π ] P wave in tauon decays. Our results will improve models used in simulation studies necessary for measuring the electric and magnetic dipole moments and Michel parameters of the \tau τ .