Study of B-0 -˃ rho(+)rho(-) decays and implications for the CKM angle phi(2)

Abstract

We present a measurement of the branching fraction and the longitudinal polarization fraction of B-0 -˃ rho(+)rho(-) decays, as well as the time-dependent CP violating parameters in decays into longitudinally polarized rho(+)rho(-) pairs with Belle's final data set of 772 x 10(6) B (B) over bar pairs, at the Upsilon(4S) resonance, collected at the asymmetric-energy e(+)e(-) collider KEKB. We obtain B(B-0 -˃ rho(+)rho(-)) = (28.3 +/- 1.5(stat) +/- 1.5(syst)) x 10(-6), f(L) = 0.988 +/- 0.012(stat) +/- 0.023(syst), A(CP) = 0.00 +/- 0.10(stat) +/- 0.06(syst), S-CP = -0.13 +/- 0.15(stat) +/- 0.05(syst). We perform an isospin analysis to constrain the Cabibbo-Kobayashi-Maskawa angle phi(2) and obtain two solutions with phi(2) = (93.7 +/- 10.6)degrees, being most compatible with other Standard-Model based fits to the data.