15 research outputs found

    Evidence for the decay X(3872) -> J/ψω

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    We present a study of the decays B-0,B-+ -> J/psi pi(+)pi(-)pi K-0(0,+), using 467 x 106 B (B) over bar pairs recorded with the BABAR detector. We present evidence for the decay mode X(3872) -> J/psi omega, with product branching fractions B(B+ -> X(3872K(+)) x B(X(3872) -> J/psi omega) = [0.6 +/- 0.2(stat) +/- 0.1(syst)] x 10(-5), and B(B-0 -> X(3872)K-0) x B(X(3872) -> J/psi omega) = [0.6 +/- 0.3(stat) +/- 0.1(syst)] x 10(-5). A detailed study of the pi(+) pi(-) pi(0) mass distribution from X(3872) decay favors a negative-parity assignment

    Search for the rare decay B→Kνν[over ¯]

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    We present a search for the rare decays B+→K+νν̅ and B0→K0νν̅ using 459×106 BB̅ pairs collected with the BABAR detector at the SLAC National Accelerator Laboratory. Flavor-changing neutral-current decays such as these are forbidden at tree level but can occur through one-loop diagrams in the standard model (SM), with possible contributions from new physics at the same order. The presence of two neutrinos in the final state makes identification of signal events challenging, so reconstruction in the semileptonic decay channels B→D(*)lν of the B meson recoiling from the signal B is used to suppress backgrounds. We set an upper limit at the 90% confidence level (CL) of 1.3×10-5 on the total branching fraction for B+→K+νν̅ , and 5.6×10-5 for B0→K0νν̅ . We additionally report 90% CL upper limits on partial branching fractions in two ranges of dineutrino mass squared for B+→K+νν̅

    Search for CP violation using T-odd correlations in D-0 -> K+K-pi(+)pi(-) decays

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    We search for CP violation in a sample of 4.7 x 10(4) Cabibbo suppressed D-0 -> K+K-pi(+)pi(-) decays. We use 470 fb(-1) of data recorded by the BABAR detector at the PEP-II asymmetric-energy e(+)e(-) storage rings running at center-of-mass energies near 10.6 GeV. CP violation is searched for in the difference between the T-odd asymmetries, obtained using triple product correlations, measured for D-0 and (D) over bar (0) decays. The measured CP violation parameter is A(T) = (1.0 +/- 5.1(stat) +/- 4.4(syst)) x 10(-3)

    Search for the rare decay B→Kνν

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    We present a search for the rare decays B+→K+νν̅ and B0→K0νν̅ using 459×106 BB̅ pairs collected with the BABAR detector at the SLAC National Accelerator Laboratory. Flavor-changing neutral-current decays such as these are forbidden at tree level but can occur through one-loop diagrams in the standard model (SM), with possible contributions from new physics at the same order. The presence of two neutrinos in the final state makes identification of signal events challenging, so reconstruction in the semileptonic decay channels B→D(*)lν of the B meson recoiling from the signal B is used to suppress backgrounds. We set an upper limit at the 90% confidence level (CL) of 1.3×10-5 on the total branching fraction for B+→K+νν̅ , and 5.6×10-5 for B0→K0νν̅ . We additionally report 90% CL upper limits on partial branching fractions in two ranges of dineutrino mass squared for B+→K+νν̅

    Measurement of CP observables in B±→D(CP)K± decays and constraints on the CKM angle γ

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    Using the entire sample of 467 x 10(6) Y(4S) -> B (B) over bar decays collected with the BABAR detector at the PEP-II asymmetric-energy B factory at the SLAC National Accelerator Laboratory, we perform an analysis of B-+/- -> DK +/- decays, using decay modes in which the neutral D meson decays to either CP-eigenstates or non-CP-eigenstates. We measure the partial decay rate charge asymmetries for CP-even and CP-odd D final states to be A(CP+) = 0.25 +/- 0.06 +/- 0.02 and A(CP-) = 0.09 +/- 0.07 +/- 0.02, respectively, where the first error is the statistical and the second is the systematic uncertainty. The parameter A(CP+) is different from zero with a significance of 3.6 standard deviations, constituting evidence for direct CP violation. We also measure the ratios of the charged-averaged B partial decay rates in CP and non-CP decays, RCP+ 1.18 +/- 0.09 +/- 0.05 and RCP- = 1.07 +/- 0.08 +/- 0.04. We infer frequentist confidence intervals for the angle gamma of the unitarity triangle, for the strong phase difference delta(B), and for the amplitude ratio r(B), which are related to the B- -> DK- decay amplitude by r(B)e(i(delta B-gamma)) = A(B- -> (D) over bar K-0(-)) = A(B- -> (D) over bar K-0(-))/A(B- -> (DK-)-K-0). Including statistical and systematic uncertainties, we obtain 0: 24 < rB < 0: 45 ( 0: 06 < rB < 0: 51) and, modulo 180 degrees, 11.3 degrees < gamma < 22.7 degrees or 80.8 degrees < gamma < 99.2 degrees or 157.3 degrees < gamma < 168.7 degrees (7.0 degrees < gamma < 173.0 degrees) at the 68% ( 95%) confidence level

    Unsaturated σ-hydrocarbyl transition-metal complexes. Part 2. Synthesis and reactions of vinylplatinum complexes and a comparison with analogous fluorovinyl and alkynyl complexes

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    Alkenyl (CHCH2 or CFCF2) or alkynyl (CCPh) derivatives of trimethyltin are shown to be superior to lithium or magnesium reagents for the synthesis of corresponding mono-organoplatinum(II) species by metathesis (L = SnMe3R +cis-[PtCl2L2]→trans-[PtRClL2]+ SnMe3Cl tertiary phosphine). The reactivity order for SnMe3R is R = CCPh > CFCF2 > CHCH2. This order is also found for oxidative addition of SnMe3R to Pt0 to give cis-[PtRL2(SnMe3)]. When the latter complex (R = CHCH2) reacts with X2 or MeX further oxidative addition occurs exclusively at the platinum centre. Aromatic isonitriles (R′NC)co-ordinate to the platinum and give insertion products trans-[Pt{C(CHCH2)= NR′}ClL2] on heating or carbene complexes with NBunH2. The alkynyl trans-[Pt(CCPh)ClL2] also forms 1 :1 adducts with R′NC and carbene complexes therefrom, but no insertion products. Spectroscopic data for the new complexes are presented

    Search for B+→D+K0 and B+→D+K*0 decays

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    We report a search for the rare decays B + → D + K 0 and B + → D + K * 0 in an event sample of approximately 465 × 10 6 B ¯¯¯ B pairs collected with the BABAR detector at the PEP-II asymmetric-energy e + e − collider at SLAC National Accelerator Laboratory. We find no significant evidence for either mode and we set 90% probability upper limits on the branching fractions of B ( B + → D + K 0 ) < 2.9 × 10 − 6 and B ( B + → D + K * 0 ) < 3.0 × 10 − 6

    Search for B+ meson decay to a(1)(+)(1260)K*(0)(892)

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    We present a search for the decay B+ -> a(1)(+)(1260)K*(0)(892). The data, collected with the BABAR detector at the SLAC National Accelerator Laboratory, represent 465 X 10(6)B (B) over bar pairs produced in e(+)e(-) annihilation at the energy of the gamma(4S). We find no significant signal and set an upper limit at 90% confidence level on the product of branching fractions B(B+ -> a(1)(+) (1260)K*(0)(892)) X B(a(1)(+)(1260) -> pi(+) pi(-) pi(+)) of 1.8 X 10(-6)

    Search for f(J)(2220) in radiative J/psi decays

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    We present a search for f(J)(2220) production in radiative J/psi --> gamma f(J)(2220) decays using 460 fb(-1) of data collected with the BABAR detector at the SLAC PEP-II e(+)e(-) collider. The f(J)(2220) is searched for in the decays to K+K- and (KSKS0)-K-0. No evidence of this resonance is observed, and 90% confidence level upper limits on the product of the branching fractions for J/psi --> gamma f(J)(2220) and f(J)(2220) --> K+K-((KSKS0)-K-0) as a function of spin and helicity are set at the level of 10(-5), below the central values reported by the Mark III experiment
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