||Amplitude analysis of epi^+pi^- at s=10.866 GeV
Garmash, A. ,
谷田 聖Belle Collaboration
072003\_16 , 2015-04 , American Physical Society
We report results on studies of the e^+e^- annihilation into three-body Upsilon(nS)pi^+pi^- (n=1,2,3) final states including measurements of cross sections and the full amplitude analysis. The cross sections measured at s = 10.866 GeV and corrected for the initial state radiation are = (2.27 0.12 0.14) pb, = (4.07 0.16 0.45) pb, = (1.46 0.09 0.16) pb. Amplitude analysis of the three-body Upsilon(nS)pi^+pi^- final states strongly favors I= 1^+(1^+) quantum-number assignments for the two bottomonium-like Zpm_b states, recently observed in the Upsilon(nS)pi^+pi^- and hpm (m=1,2) decay channels. The results are obtained with a 121.4 fb-1 data sample collected with the Belle detector at the KEKB asymmetric-energy e^+e^- collider.