Study of via initial state radiation at Belle

Zhu, W. J.*; Tanida, Kiyoshi   ; Belle Collaboration*; 174 of others*

Using of data collected on and around the resonances with the Belle detector at the KEKB collider, we measure the cross section of from threshold to via initial-state radiation. From a multi-parameter fit assuming exists in the final state according to previous measurement by BESIII, the resonant parameters of are determined to be (statistical and systematic errors, respectively), and, depending on the possible presence of interfering resonances, , , or . The branching fraction of decay is determined to be approximately 20%. Additionally, the branching fraction for is measured to be . However, there is no significant observed signal in the final states in this analysis, and correspondingly the upper limit for is determined to be either (for two fits), or (remaining two fits), at 90% confidence level.