Ablikim, M.Achasov, M. N.Adlarson, P.Albrecht, M.Aliberti, R.Amoroso, A.Çetin, Serkant Ali2024-05-192024-05-1920232470-00102470-0029https://doi.org10.1103/PhysRevD.107.092007https://hdl.handle.net/20.500.12713/5809A precision measurement of the matrix elements for eta -> pi(+)pi(-)pi(0) and -> pi(0)pi(0)pi(0) decays is performed using a sample of (10087 +/- 44) x 10(6) J/psi decays collected with the BESIII detector. The decay J/psi -> gamma eta is used to select clean samples of 631, 686 eta -> pi(+)pi(-)pi(0) decays and 272, 322 eta -> pi(0)pi(0)pi(0) decays. The matrix elements for both channels are in reasonable agreement with previous measurements. The nonzero gX(2)Y term for the decay mode eta -> pi(+)pi(-)pi(0) is confirmed, as reported by the KLOE Collaboration, while the other higher-order terms are found to be insignificant. Dalitz plot asymmetries in the eta -> pi(+)pi(-)pi(0) decay are also explored and are found to be consistent with charge conjugation invariance. In addition, a cusp effect is investigated in the eta -> pi(0)pi(0)pi(0) decay, and no obvious structure around the pi(+)pi(-) mass threshold is observed.eninfo:eu-repo/semantics/openAccessCharge AsymmetryDynamics3-PiArticle1079WOS:001020823800002N/A10.1103/PhysRevD.107.092007