We present results from an analysis of B-0 ->rho(+)rho(-) decays using (383.6 +/- 4.2)x10(6) B (B) over bar pairs collected by the BABAR detector at the PEP-II asymmetric-energy B factory at SLAC. The measurements of the B-0 ->rho(+)rho(-) branching fraction, longitudinal polarization fraction f(L), and the CP-violating parameters S-long and C-long are as follows: B(B-0 ->rho(+)rho(-))=(25.5 +/- 2.1(stat)(-3.9)(+3.6)(syst))x10(-6), f(L)=0.992 +/- 0.024(stat)(-0.013)(+0.026)(syst), S-long=-0.17 +/- 0.20(stat)(-0.06)(+0.05)(syst), C-long=0.01 +/- 0.15(stat)+/- 0.06(syst). We determine the unitarity triangle angle alpha, using an isospin analysis of B ->rho rho decays. One of the two solutions, alpha={[}73.1,117.0]degrees at 68\% confidence level, is compatible with standard model-based fits of existing data. Constraints on the unitarity triangle are also evaluated using an SU(3) symmetry-based approach.

Study of B-0 -> rho(+)rho(-) decays and constraints on the CKM angle alpha

BIANCHI, Fabrizio;GAMBA, Diego;
2007-01-01

Abstract

We present results from an analysis of B-0 ->rho(+)rho(-) decays using (383.6 +/- 4.2)x10(6) B (B) over bar pairs collected by the BABAR detector at the PEP-II asymmetric-energy B factory at SLAC. The measurements of the B-0 ->rho(+)rho(-) branching fraction, longitudinal polarization fraction f(L), and the CP-violating parameters S-long and C-long are as follows: B(B-0 ->rho(+)rho(-))=(25.5 +/- 2.1(stat)(-3.9)(+3.6)(syst))x10(-6), f(L)=0.992 +/- 0.024(stat)(-0.013)(+0.026)(syst), S-long=-0.17 +/- 0.20(stat)(-0.06)(+0.05)(syst), C-long=0.01 +/- 0.15(stat)+/- 0.06(syst). We determine the unitarity triangle angle alpha, using an isospin analysis of B ->rho rho decays. One of the two solutions, alpha={[}73.1,117.0]degrees at 68\% confidence level, is compatible with standard model-based fits of existing data. Constraints on the unitarity triangle are also evaluated using an SU(3) symmetry-based approach.
2007
76
052007
0520014
B. Aubert; M. Bona; D. Boutigny; Y. Karyotakis; J. P. Lees; V. Poireau; X. Prudent; V. Tisserand; A. Zghiche; J. Garra Tico; E. Grauges; L. Lopez; A. ...espandi
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/2318/43403
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