We present a study of the branching fraction of the decay B-0 -> rho(0)rho(0) and the fraction of longitudinally polarized rho(0) mesons in this decay. The results are obtained from the final data sample containing 772 x 10(6) B (B) over bar pairs collected at the gamma(4S) resonance with the Belle detector at the KEKB asymmetric-energy e(+)e(-) collider. We find 166 +/- 59 B-0 -> rho(0)rho(0) events (including systematic uncertainties), corresponding to a branching fraction of B(B-0 -> rho(0)rho(0)) = (1.02 +/- 0.30(stat) +/- 0.15(syst)) x 10(-6) with a significance of 3.4 standard deviations and a longitudinal polarization fraction f(L) = 0.21(-0.22)(+0.18()stat) +/- 0.15(syst). We use the longitudinal polarization fraction to determine the Cabibbo-Kobayashi-Maskawa matrix angle phi(2) = (84.9 +/- 13.5)degrees through an isospin analysis in the B ->rho rho system. We furthermore find 125 +/- 41 B-0 -> f(0)rho(0) events, corresponding to B(B-0 -> f(0)rho(0)) x B(f(0) -> pi(+)pi(-)) = (0.78 +/- 0.22(stat) +/- 0.11(syst)) x 10(-6), with a significance of 3.1 standard deviations. We find no other significant contribution with the same final state, and set upper limits at 90% confidence level on the (product) branching fractions, B(B-0 -> pi(+)pi(-)pi(+)pi(-)) < 11.2 x 10(-6), B(B-0 -> rho(0)pi(+)pi(-)) < 12.0 x 10(-6), B(B-0 -> f(0)pi(+)pi(-)) x B(f(0) -> pi(+)pi(-)) < 3.0 x 10(-6) and B(B-0 -> f(0)f(0)) x B(f(0) -> pi(+)pi(-))(2) < 0.2 x 10(-6).
Jian Wang, Matthias Finger, Qian Wang, Yiming Li, Matthias Wolf, Varun Sharma, Yi Zhang, Konstantin Androsov, Jan Steggemann, Leonardo Cristella, Xin Chen, Davide Di Croce, Rakesh Chawla, Matteo Galli, Anna Mascellani, João Miguel das Neves Duarte, Tagir Aushev, Lei Zhang, Tian Cheng, Yixing Chen, Werner Lustermann, Andromachi Tsirou, Alexis Kalogeropoulos, Andrea Rizzi, Ioannis Papadopoulos, Paolo Ronchese, Hua Zhang, Siyuan Wang, Tao Huang, David Vannerom, Michele Bianco, Sebastiana Gianì, Sun Hee Kim, Kun Shi, Wei Shi, Abhisek Datta, Jian Zhao, Federica Legger, Gabriele Grosso, Ji Hyun Kim, Donghyun Kim, Zheng Wang, Sanjeev Kumar, Wei Li, Yong Yang, Ajay Kumar, Ashish Sharma, Georgios Anagnostou, Joao Varela, Csaba Hajdu, Muhammad Ahmad, Ekaterina Kuznetsova, Ioannis Evangelou, Muhammad Shoaib, Milos Dordevic, Meng Xiao, Sourav Sen, Xiao Wang, Kai Yi, Jing Li, Rajat Gupta, Muhammad Waqas, Hui Wang, Seungkyu Ha, Pratyush Das, Miao Hu, Anton Petrov, Xin Sun, Valérie Scheurer, Muhammad Ansar Iqbal, Lukas Layer
Riccardo Rattazzi, Angelo Esposito, Alfredo Glioti
Andrea Guerrieri, Denis Karateev, Kelian Philippe Häring