Study of the η → π⁺π⁻π⁰ decay in p − p collisions with WASA-at-COSY

M. Smoluchowski Institute of Physics, Jagiellonian University, Reymonta 4, 30-059 Cracow, Poland

^a e-mail: wiktor.bardan@uj.edu.pl

Abstract

Study of the η → π⁺π⁻π⁰ decay allows for precise tests of the C parity conservation, makes possible to set constraints on the u and d as well as s and d quark mass ratios and can be used for a verification of the predictions of the Chiral Perturbation Theory (ChPT). The WASA-at-COSY collaboration has accumulated the world largest numbers of η mesons produced in p − d and p − p collisions. This report includes preliminary results of the ongoing analysis of the η → π⁺π⁻π⁰ decay from p − p data which were collected during 8 weeks of the COSY beam time in 2010 in Forschungszentrum Jülich with more than 10⁸ η mesons produced.