Belle CollaborationVanhoefer, P.Dalseno, J.Kiesling, C.Adachi, I.Aihara, H.Asner, D. M.Aulchenko, V.Aushev, T.Bakich, A. M.Bala, A.Bhardwaj, V.Bhuyan, B.Bonvicini, G.Bozek, A.Bracko, M.Browder, T. E.Chang, M. -C.Chang, P.Chekelian, V.Chen, A.Chen, P.Cheon, B. G.Chilikin, K.Chistov, R.Cho, K.Chobanova, V.Choi, Y.Cinabro, D.Dolezal, Z.Drasal, Z.Eidelman, S.Farhat, H.Fast, J. E.Ferber, T.Gaur, V.Gabyshev, N.Ganguly, S.Garmash, A.Gillard, R.Goh, Y. M.Golob, B.Hara, T.Hayasaka, K.Hayashii, H.Higuchi, T.Horii, Y.Hoshi, Y.Hou, W. -S.Hyun, H. J.Iijima, T.Ishikawa, A.Itoh, R.Iwasaki, Y.Iwashita, T.Jaegle, I.Julius, T.Kah, D. H.Kato, E.Kawai, H.Kawasaki, T.Kim, D. Y.Kim, H. O.Kim, J. B.Kim, J. H.Kim, M. J.Kim, Y. J.Kinoshita, K.Klucar, J.Ko, B. R.Korpar, S.Krizan, P.Krokovny, P.Kronenbitter, B.Kuhr, T.Kumita, T.Kuzmin, A.Kwon, Y. -J.Lange, J. S.Lee, S. -H.Li, J.Gioi, L. LiLibby, J.Liu, C.Liu, Y.Liventsev, D.Lukin, P.Miyabayashi, K.Miyata, H.Mizuk, R.Mohanty, G. B.Moll, A.Moser, H. -G.Mussa, R.Nakano, E.Nakao, M.Natkaniec, Z.Nedelkovska, E.Nisar, N. K.Nishida, S.Nitoh, O.Ogawa, S.Pakhlov, P.Pakhlova, G.Park, C. W.Park, H.Park, H. K.Pedlar, T. K.Pestotnik, R.Petric, M.Piilonen, L. E.Ritter, M.Roehrken, M.Rostomyan, A.Ryu, S.Sahoo, H.Saito, T.Sakai, Y.Sandilya, S.Santelj, L.Sanuki, T.Sato, Y.Savinov, V.Schneider, O.Schnell, G.Schwanda, C.Schwartz, A. J.Semmler, D.Senyo, K.Seon, O.Sevior, M. E.Shapkin, M.Shen, C. P.Shibata, T. -A.Shiu, J. -G.Shwartz, B.Sibidanov, A.Simon, F.Sohn, Y. -S.Sokolov, A.Solovieva, E.Staric, M.Steder, M.Sumiyoshi, T.Tamponi, U.Tatishvili, G.Teramoto, Y.Trabelsi, K.Tsuboyama, T.Uchida, M.Uehara, S.Unno, Y.Uno, S.Vahsen, S. E.Van Hulse, C.Varner, G.Varvell, K. E.Vinokurova, A.Vorobyev, V.Wagner, M. N.Wang, C. H.Wang, M. -Z.Wang, P.Wang, X. L.Watanabe, Y.Williams, K. M.Won, E.Yamashita, Y.Yashchenko, S.Yook, Y.Zhang, Z. P.Zhilich, V.Zhulanov, V.Zupanc, A.2014-05-192014-05-192014-05-19201410.1103/PhysRevD.89.072008https://infoscience.epfl.ch/handle/20.500.14299/103444WOS:000334316800003We 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).text::journal::journal article::research article