Study of $f_1(1420)$ and $\hat{I}\cdot (1405)$ in the decay $J/\ddot{I}ˆ\to {\hat{I}}^3\ddot{I}{€}^0\ddot{I}{€}^0\ddot{I}{€}^0$

Abstract

A partial-wave analysis is performed on the decay $J/\ddot{I}ˆ\to {\hat{I}}^3\ddot{I}{€}^0\ddot{I}{€}^0\ddot{I}{€}^0$ within the $\ddot{I}{€}^0\ddot{I}{€}^0\ddot{I}{€}^0$ invariant-mass region below 1.6 GeV$/c^2$, using $(10.09\pm 0.04)\times 10^{9}J/\ddot{I}ˆ$ events collected with the BESIII detector. Significant isospin-violating decays of $\hat{I}\cdot (1405)$ and $f_1(1420)$ into $f_0(980)\ddot{I}{€}^0$ are observed. For the first time, three axial-vectors, $f_1(1285)$, $f_1(1420)$ and $f_1(1510)$, are observed to decay into $\ddot{I}{€}^0\ddot{I}{€}^0\ddot{I}{€}^0$. The product branching fractions of these resonances are reported.