@phdthesis{oai:tsukuba.repo.nii.ac.jp:00008682,
 author = {Zhang, Jingzhi and 張, 景芝},
 month = {},
 note = {In this dissertation, we report the first observation of the charmless vector-vector decay mode B+[?]ρ+ρ0. The measurement is based on a 78fb-1 data sample collected with the Belle detector at the KBKB asymmetric e+e- colider operating at the Υ(4S) resonance. We obtain the branching fraction of B(B+[?]ρ+ρ0)=(31.7[?]7.1(stat.)[?]3.9(sys.)[?](pol.))X10-6. From an analysis of the ρ helicity-angle deistributions, we obtain a longitudinal polarization ratio, ΓL/Γ=(94.8[?]10.6(stat.)[?]2.1(sys.))%. We also measure a partial rate asymmetry Acp(B[?][?]ρ[?]ρ0)=(0.1[?]22.4(stat.)[?](sys.))%., 2002, Includes bibliographical references},
 school = {筑波大学, University of Tsukuba},
 title = {Study of the branching ratio of B → ρρ decays at the Belle experiment},
 year = {2003}
}