e+e- → π+π -π+π-, K+K -π+π-, and K+K -K+K- cross sections at center-of-mass energies 0.5-4.5 GeV measured with initial-state radiation
Physical Review D - Particles, Fields, Gravitation and Cosmology 71:5 (2005) 1-25
Abstract:
We study the process e+e- → π+π -π+π-γ, with a hard photon radiated from the initial state. About 60 000 fully reconstructed events have been selected from 89 fb-1 of BABAR data. The invariant mass of the hadronic final state defines the effective e+e- e +e- center-of-mass energy, so that these data can be compared with the corresponding direct e+e- measurements. From the 4π -mass spectrum, the cross section for the process e +e- → π+π -π+π- is measured for center-of-mass energies from 0.6 to 4.5 GeV. The uncertainty in the cross section measurement is typically 5%. We also measure the cross sections for the final states K +K-π+π- and K +K-K+K-. We observe the J/ψ in all three final states and measure the corresponding branching fractions. We search for X(3872) in Jψ(→ μ+μ-) π+π- and obtain an upper limit on the product of the e+e- width of the X(3872) and the branching fraction for X(3872) → Jψπ+π-. © 2005 The American Physical Society.Measurements of the branching fraction and CP-violation asymmetries in B0 f0 (980)KS 0
Physical Review Letters 94:4 (2005)
Abstract:
We present measurements of the branching fraction and CP-violating asymmetries in the decay B0 → f0(980)K s0. The results are obtained from a data sample of 123 × 106 Y(4S) → BB̄ decays. From a time-dependent maximum likelihood fit, we measure the branching fraction B(B0 → f0(980)(→ π+ π-)K0) = (6.0 ± 0.9 ± 0.6 ± 1.2) × 10-6, the mixing-induced CP violation parameter S = -1.62-0.51+0.56 ± 0.09 ± 0.04, and the direct CP violation parameter C = 0.27 ± 0.36 ± 0.10 ± 0.07, where the first errors are statistical, the second systematic, and the third due to model uncertainties. We measure the f0 (980) mass and width to be mf(980) = (980.6±4.1± 0.5±4.0)MeV/c2 and Γf0(980) = (43-9+12±3±9) MeV/c2, respectively. © 2005 The American Physical Society.Measurement of the ratio B(B- → D*0K -)/B(B → D*0π-) and of the CP asymmetry of B- → D*CP+ 0K - decays
Physical Review D - Particles, Fields, Gravitation and Cosmology 71:3 (2005) 031102-1-031102-8
Abstract:
We study the decays B- → D*0π - and B-→ D*0K-, where the D*0 decays into D0π0, with the D0 reconstructed in the CP-even (CP+) eigenstates K-K + and π-π+ and in the (non-CP) channels K-π+, K -π+π+π-, and K -π+π0. Using a sample of about 123 × 106 BB̄ pairs, we measure the ratios of decay rates R*non-CP ≡ B(B- → D* non-CP 0K-)/B(B- → D*non-CP 0π-) = 0.086 ± 0.0040(stat)-0.0031 +0.0042(syst), and provide the first measurements of R*CP+ ≡ B(B- → D*CP+ 0K-)/B(B- → D*CP+ 0π-) = 0.0086 ± 0.021(stat) ± 0.007(syst), and of the CP asymmetry A*CP+ ≡ B(B- → D*CP+ 0K -)-B(B+ → D*CP+ 0K +)/B(B- → D*CP+ 0K -)+B(B+ → D*CP+ 0K +) = 0.10 ± 0.23(stat)-0.04 +0.03(syst). © 2005 The American Physical Society.Measurements of B meson decays to ωK* and ωρ
Physical Review D - Particles, Fields, Gravitation and Cosmology 71:3 (2005) 031103-1-031103-9
Abstract:
We describe searches for B meson decays to the charmless vector-vector final states ωK* and ωρ in 89 × 106 BB̄ pairs produced in e+e- annihilation at √s = 10.58 GeV. We measure the following branching fractions in units of 10 -6: B(B0 → ωK*0) = 3.4 -1.6 +1.8 ± 0.4(<6.0), B(B+ → ωK*+) = 3.5-2.0 +2.5 ± 0.7(<7.4), B(B0 → ωρ0) = 0.6 -1.1 +1.3 ± 0.4(<3.3), and B(B+ → ωρ+) = 12.6-3.3 +3.7 ± 1.6. The first error quoted is statistical, the second systematic, and the upper limits are defined at 90% confidence level. For B+ → ωρ+ we also measure the longitudinal spin alignment fraction fL = 0.88-0.15 +0.12 ± 0.03 and charge asymmetry Ach = (5 ± 26 ± 2)%. © 2005 The American Physical Society.Search for a charged partner of the X(3872) in the B meson decay B → X-K, X- → J/ψπ-π0
Physical Review D - Particles, Fields, Gravitation and Cosmology 71:3 (2005) 031501-1-031501-8