2,042 research outputs found
Dalitz plot analyses of B-0 -> (D-DK+)-K-0 and B+-> (D)over-bar(-)D(0)K(+) decays
No full text© 2015, APS Journal
Search for the decay modes D-0 -> e(+) e(-), D-0 -> mu(+) mu(-), and D-0 -> e(+/-) mu -/+
No full textWe present searches for the rare decay modes D-0 -> e(+) e(-), D-0 -> mu(+) mu(-), and D-0 -> e(+/-) mu(-/+) in continuum e(+) e(-) -> c (c) over bar events recorded by the BABAR detector in a data sample that corresponds to an integrated luminosity of 468 fb(-1). These decays are highly Glashow-Iliopoulos-Maiani suppressed but may be enhanced in several extensions of the standard model. Our observed event yields are consistent with the expected backgrounds. An excess is seen in the D-0 -> mu(+) mu(-) channel, although the observed yield is consistent with an upward background fluctuation at the 5% level. Using the Feldman-Cousins method, we set the following 90% confidence level intervals on the branching fractions: B(D-0 -> e(+) e(-)) mu(+) mu(-)) within [0.6,8.1] x 10(-7), and B(D-0 -> e(+/-) mu(-/+)) < 3.3 x 10(-7). RI Monge, Maria Roberta/G-9127-2012; Patrignani, Claudia/C-5223-200
Dalitz plot analyses of B-0 -> (D-DK+)-K-0 and B+-> (D)over-bar(-)D(0)K(+) decays
No full textWe present Dalitz plot analyses for the decays of B mesons to (D-DK+)-K-0 and (D) over bar (DK+)-D-0-K-0. We report the observation of the D*(s1)(2700)(+) resonance in these two channels and obtain measurements of the mass M(D*(s1)(2700)(+)) = 2699(-7)(+14) MeV/c(2) and of the width Gamma(D*(s1)(2700)(+)) = 127(-19)(+24) MeV, including statistical and systematic uncertainties. In addition, we observe an enhancement in the (DK+)-K-0 invariant mass around 2350-2500 MeV/c(2) in both decays B-0 -> (D-DK+)-K-0 and B+ -> (D) over bar (DK+)-D-0-K-0, which we are not able to interpret. The results are based on 429 fb(-1) of data containing 471 x 10(6) B (B) over bar pairs collected at the Upsilon(4S) resonance with the BABAR detector at the SLAC National Accelerator Laboratory
Exclusive production of Ds+Ds-,D-s*D-+(s)-, and D-s*D-+(s)*(-) via e(+)e(-) annihilation with initial-state radiation
No full textWe perform a study of exclusive production of Ds+Ds-,D-s*(+),D-s(-), and D-s*D-+(s)*- final states in initial-state radiation events from e(+)e(-) annihilations at a center-of-mass energy near 10.58 GeV, to search for charmonium 1(--) states. The data sample corresponds to an integrated luminosity of 525 fb(-1) and was recorded by the BABAR experiment at the PEP-II storage ring. Ds+Ds-,D-s*(+),D-s(-) and ,D-s*(+),D-s*(-) mass spectra show evidence of the known psi resonances. Limits are extracted for the branching ratios of the decays X(4260) -> D-s(()*()+) D-s(()*()-
Measurement of the D[superscript *](2010)[superscript +] natural linewidth and the D[superscript *](2010)[superscript +] - D[superscript 0] mass difference
No full textWe measure the mass difference, Δm[subscript 0], between the D[superscript *](2010)[superscript +] and the D[superscript 0] and the natural linewidth, Γ, of the transition D[superscript *](2010)[superscript +] → D[superscript 0]π[superscript +]. The data were recorded with the BABAR detector at center-of-mass energies at and near the Υ(4S) resonance, and correspond to an integrated luminosity of approximately 477 fb[superscript −1]. The D[superscript 0] is reconstructed in the decay modes D[superscript 0] → K[superscript −]π[superscript +] and D[superscript 0] → K[superscript −]π[superscript +]π[superscript −]π[superscript +]. For the decay mode D[superscript 0] → K[superscript −]π[superscript +] we obtain Γ = (83.4 ± 1.7 ± 1.5) keV and Δm[subscript 0] = (145425.6 ± 0.6 ± 1.8) keV, where the quoted errors are statistical and systematic, respectively. For the D[superscript 0] → K[superscript −]π[superscript +]π[superscript −]π[superscript +] mode we obtain Γ = (83.2 ± 1.5 ± 2.6) keV and Δm[subscript 0] = (145426.6 ± 0.5 ± 2.0) keV. The combined measurements yield Γ = (83.3 ± 1.2 ± 1.4) keV and Δm[subscript 0] = (145425.9 ± 0.4 ± 1.7) keV; the width is a factor of approximately 12 times more precise than the previous value, while the mass difference is a factor of approximately 6 times more precise.United States. Dept. of EnergyNational Science Foundation (U.S.)Alfred P. Sloan Foundatio
Search for the decay modes D-0 -> e(+) e(-), D-0 -> mu(+) mu(-), and D-0 -> e(+/-) mu -/+
No full textWe present searches for the rare decay modes D-0 -> e(+) e(-), D-0 -> mu(+) mu(-), and D-0 -> e(+/-) mu(-/+) in continuum e(+) e(-) -> c (c) over bar events recorded by the BABAR detector in a data sample that corresponds to an integrated luminosity of 468 fb(-1). These decays are highly Glashow-Iliopoulos-Maiani suppressed but may be enhanced in several extensions of the standard model. Our observed event yields are consistent with the expected backgrounds. An excess is seen in the D-0 -> mu(+) mu(-) channel, although the observed yield is consistent with an upward background fluctuation at the 5% level. Using the Feldman-Cousins method, we set the following 90% confidence level intervals on the branching fractions: B(D-0 -> e(+) e(-)) mu(+) mu(-)) within [0.6,8.1] x 10(-7), and B(D-0 -> e(+/-) mu(-/+)) < 3.3 x 10(-7)
Dalitz plot analyses of B-0 -> (D-DK+)-K-0 and B+-> (D)over-bar(-)D(0)K(+) decays
No full textWe present Dalitz plot analyses for the decays of B mesons to (D-DK+)-K-0 and (D) over bar (DK+)-D-0-K-0. We report the observation of the D*(s1)(2700)(+) resonance in these two channels and obtain measurements of the mass M(D*(s1)(2700)(+)) = 2699(-7)(+14) MeV/c(2) and of the width Gamma(D*(s1)(2700)(+)) = 127(-19)(+24) MeV, including statistical and systematic uncertainties. In addition, we observe an enhancement in the (DK+)-K-0 invariant mass around 2350-2500 MeV/c(2) in both decays B-0 -> (D-DK+)-K-0 and B+ -> (D) over bar (DK+)-D-0-K-0, which we are not able to interpret. The results are based on 429 fb(-1) of data containing 471 x 10(6) B (B) over bar pairs collected at the Upsilon(4S) resonance with the BABAR detector at the SLAC National Accelerator Laboratory
Measurement of the mass of the D[superscript 0] meson
No full textWe report a measurement of the D[superscript 0] meson mass using the decay chain D[superscript *](2010)[superscript +] → D[superscript 0]π[superscript +] with D[superscript 0] → K[superscript −]K[superscript −]K[superscript +]π[superscript +]. The data were recorded with the BABAR detector at center-of-mass energies at and near the Υ(4S) resonance, and correspond to an integrated luminosity of approximately 477 fb[superscript −1]. We obtain m(D[superscript 0]) = (1864.841 ± 0.048 ± 0.063) MeV, where the quoted errors are statistical and systematic, respectively. The uncertainty of this measurement is half that of the best previous measurement.United States. Dept. of EnergyNational Science Foundation (U.S.)Alfred P. Sloan Foundatio
Measurement of D[superscript 0]-D̅[superscript 0] mixing and CP violation in two-body D[superscript 0] decays
No full textWe present a measurement of D[superscript 0]-D̅[superscript 0] mixing and CP violation using the ratio of lifetimes simultaneously extracted from a sample of D[superscript 0] mesons produced through the flavor-tagged process D[superscript *+]→D[superscript 0]π[superscript +], where D[superscript 0] decays to K[superscript ∓]π[superscript ±], K[superscript -]K[superscript +], or π[superscript -]π[superscript +], along with the untagged decays D[superscript 0]→K[superscript ∓]π[superscript ±] and D[superscript 0]→K[superscript -]K[superscript +]. The lifetimes of the CP-even, Cabibbo-suppressed modes K[superscript -]K[superscript +] and π[superscript -]π[superscipt +] are compared to that of the CP-mixed mode K[superscript ∓]π[superscript ±] in order to measure y[subscript CP] and ΔY. We obtain y[subscript CP]=[0.72±0.18(stat)±0.12(syst)]% and ΔY=[0.09±0.26(stat)±0.06(syst)]%, where ΔY constrains possible CP violation. The y[subscript CP] result excludes the null mixing hypothesis at 3.3σ significance. This analysis is based on an integrated luminosity of 468 fb[superscript -1] collected with the BABAR detector at the PEP-II asymmetric-energy e[superscript +]e[superscript -] collider.Alfred P. Sloan Foundatio
Measurement of branching fractions of color-suppressed decays of the (B)over-bar(0) meson to D-(*)0 pi(0), D-(*)0 eta, D-(*)0 omega, and D-0 eta `
No full textUsing a sample of 88.8×10^6 BB̅ events collected with the BABAR detector at the PEP-II storage rings at the Stanford Linear Accelerator Center, we measure the branching fractions of seven color-suppressed B-meson decays: B(B0→D0π0)=[2.9±0.2(stat)±0.3(syst)]×10-4, B(B0→D*0π0)=[2.9±0.4(stat)±0.5(syst)]×10-4, B(B0→D0η)=[2.5±0.2(stat)±0.3(syst)]×10-4, B(B0→D*0η)=[2.6±0.4(stat)±0.4(syst)]×10-4, B(B0→D0ω)=[3.0±0.3(stat)±0.4(syst)]×10-4, B(B0→D*0ω)=[4.2±0.7(stat)±0.9(syst)]×10-4, and B(B0→D0η′)=[1.7±0.4(stat)±0.2(syst)]×10-4. We set the 90% confidence-level upper limit: B(B0→D*0η′)<2.6×10-4. The channels B0→D*0η, D*0ω, and D0η′ are seen with more than five-sigma statistical significance. All of these branching fractions are significantly larger than theoretical expectations based on the “naive” factorization model
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