Evidence for B{sup 0}{yields}{rho}{sup 0}{rho}{sup 0} Decays and Implications for the Cabibbo-Kobayashi-Maskawa Angle {alpha}

Journal Article · Fri Mar 16 04:00:00 EDT 2007 · Physical Review Letters

DOI:https://doi.org/10.1103/PHYSREVLETT.98.111801· OSTI ID:20957745

Aubert, B; Bona, M; Boutigny, D; Karyotakis, Y; Lees, J P; Poireau, V; Prudent, X; Tisserand, V; Zghiche, A ^[1]; Grauges, E ^[2]; Palano, A ^[3]; Chen, J C; Qi, N D; Rong, G; Wang, P; Zhu, Y S ^[4]; Eigen, G; Ofte, I; Stugu, B ^[5]; Abrams, G S ^[6]

---

1. Laboratoire de Physique des Particules, IN2P3/CNRS et Universite de Savoie, F-74941 Annecy-Le-Vieux (France)
2. Universitat de Barcelona, Facultat de Fisica, Departament ECM, E-08028 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)
6. Lawrence Berkeley National Laboratory and University of California, Berkeley, California 94720 (United States)

We search for the decays B{sup 0}{yields}{rho}{sup 0}{rho}{sup 0}, B{sup 0}{yields}{rho}{sup 0}f{sub 0}(980), and B{sup 0}{yields}f{sub 0}(980)f{sub 0}(980) in a sample of about 384x10{sup 6} {upsilon}(4S){yields}BB decays collected with the BABAR detector at the PEP-II asymmetric-energy e{sup +}e{sup -} collider at Stanford Linear Accelerator Center. We find evidence for B{sup 0}{yields}{rho}{sup 0}{rho}{sup 0} with 3.5{sigma} significance and measure the branching fraction B=(1.07{+-}0.33{+-}0.19)x10{sup -6} and longitudinal polarization fraction f{sub L}=0.87{+-}0.13{+-}0.04, where the first uncertainty is statistical, and the second is systematic. The uncertainty on the Cabibbo-Kobayashi-Maskawa quark-mixing matrix unitarity angle {alpha} due to penguin contributions in B{yields}{rho}{rho} decays is 18 deg. at the 1{sigma} level. We also set upper limits on the B{sup 0}{yields}{rho}{sup 0}f{sub 0}(980) and B{sup 0}{yields}f{sub 0}(980)f{sub 0}(980) decay rates.

• OSTI ID: 20957745
• Journal Information: Physical Review Letters, Journal Name: Physical Review Letters Journal Issue: 11 Vol. 98; 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
BRANCHING RATIO
CABIBBO ANGLE
F0-980 MESONS
KOBAYASHI-MASKAWA MATRIX
PAIR PRODUCTION
PARTICLE DECAY
POLARIZATION
QUARKS
RHO-770 MESONS
STANFORD LINEAR ACCELERATOR CENTER
UNITARITY