Improved Measurement of the Cabibbo-Kobayashi-Maskawa Angle {alpha} Using B{sup 0}(B){yields}{rho}{sup +}{rho}{sup -} Decays

Journal Article · Fri Jul 22 00:00:00 EDT 2005 · Physical Review Letters

DOI:https://doi.org/10.1103/PhysRevLett.95.041805· OSTI ID:20696469

Aubert, B; Barate, R; Boutigny, D; Couderc, F; Karyotakis, Y; Lees, J P; Poireau, V; Tisserand, V; Zghiche, A ^[1]; Grauges, E ^[2]; Palano, A; Pappagallo, M; Pompili, A ^[3]; Chen, J C; Qi, N D; Rong, G; Wang, P; Zhu, Y S ^[4]; Eigen, G; Ofte, I ^[5]

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1. Laboratoire de Physique des Particules, F-74941 Annecy-le-Vieux (France)
2. IFAE, Universitat Autonoma de Barcelona, E-08193 Bellaterra, Barcelona (Spain)
3. Universita di Bari, Dipartimento di Fisica and INFN, I-70126 Bari (Italy)
4. Institute of High Energy Physics, Beijing 100039 (China)
5. University of Bergen, Institute of Physics, N-5007 Bergen (Norway); and others

We present results from an analysis of B{sup 0}(B{sup 0}){yields}{rho}{sup +}{rho}{sup -} using 232x10{sup 6} {upsilon}(4S){yields}BB decays collected with the BABAR detector at the PEP-II asymmetric-energy B factory at SLAC. We measure the longitudinal polarization fraction f{sub L}=0.978{+-}0.014(stat)(+0.021/-0.029)(syst) and the CP-violating parameters S{sub L}=-0.33{+-}0.24(stat)(+0.08/-0.14)(syst) and C{sub L}=-0.03{+-}0.18(stat){+-}0.09(syst). Using an isospin analysis of B{yields}{rho}{rho} decays, we determine the unitarity triangle parameter {alpha}. The solution compatible with the standard model is {alpha}=(100{+-}13) deg.

• OSTI ID: 20696469
• Journal Information: Physical Review Letters, Journal Name: Physical Review Letters Journal Issue: 4 Vol. 95; ISSN 0031-9007; ISSN PRLTAO
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
ASYMMETRY
B NEUTRAL MESONS
CABIBBO ANGLE
CP INVARIANCE
HADRONIC PARTICLE DECAY
ISOSPIN
KOBAYASHI-MASKAWA MATRIX
MATHEMATICAL SOLUTIONS
POLARIZATION
STANDARD MODEL
STANFORD LINEAR ACCELERATOR CENTER
UNITARITY
VECTOR MESONS