Three-particle formalism for multiple channels: the ηππ + $$ K\overline{K}\pi $$ system in isosymmetric QCD

• Published in: The journal of high energy physics 2024-07, Vol.2024 (7), Article 83
• Main Authors: Draper, Zachary T., Sharpe, Stephen R.
• Format: Article
• Language: English
• Subjects: Hadronic Spectroscopy; Lattice QCD; PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; Structure and Interactions
• ISSN: 1029-8479; 1029-8479
• DOI: 10.1007/JHEP07(2024)083

We generalize previous three-particle finite-volume formalisms to allow for multiple three-particle channels. For definiteness, we focus on the two-channel ηππ and $$ K\overline{K}\pi $$ K K ¯ π system in isosymmetric QCD, considering the positive G parity sector of the latter channel, and neglecting the coupling to modes with four or more particles. The formalism we obtain is thus appropriate to study the b 1 (1235) and η (1295) resonances. The derivation is made in the generic relativistic field theory approach using the time-ordered perturbation theory method. We study how the resulting quantization condition reduces to that for a single three-particle channel when one drops below the upper ( $$ K\overline{K}\pi $$ K K ¯ π ) threshold. We also present parametrizations of the three-particle K matrices that enter into the formalism.