Abstract
Using a data sample of 106 million events collected with the BESIII detector operated at the BEPCII storage ring, we study for the first time the decays and in the E1 radiative transition . The decays are dominated by the three-body decay . We measure branching fractions for this reaction via the neutral and charged and find them consistent with each other within the expectation of isospin symmetry. In the invariant mass distribution, a structure near the mass threshold is observed, and the corresponding mass and width are measured to be and , respectively. The observed state favors an assignment to the , considering its possible and comparing its mass, width and decay mode to those reported in the Particle Data Group.
1 More- Received 16 March 2015
DOI:https://doi.org/10.1103/PhysRevD.91.112008
© 2015 American Physical Society