Publications (718)1676.16 Total impact

Article: Observation of B^+ to Phi Phi K^+ and Evidence for B^0 to Phi Phi K^0 below Eta_C Threshold
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ABSTRACT: The authors report measurements of the decays B{sup +} â ÏÏK{sup +} and BÂ° â ÏÏKÂ° using a sample of 231 million B{bar B} pairs collected with the BABAR detector at the PEPII asymmetricenergy B Factory at the Stanford Linear Accelerator Center. The branching fractions are measured to be Î(B{sup +} â ÏÏK{sup +}) = (7.5 {+} 1.0(stat) {+} 0.7(syst)) x 10â»â¶ and Î(BÂ° â ÏÏKÂ°) = (4.1{sub 1.4}{sup +1.7}(stat) {+} 0.4(syst)) x 10â»â¶ for a ÏÏ invariant mass below 2.85 GeV/cÂ². 
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ABSTRACT: We present results for the moments of observed spectra in inclusive semileptonic Bmeson decays to charm hadrons B̅ →X_cℓ^ν̅ . Moments of the hadronicmass and the combined massandenergy spectra for different minimum electron or muon momenta between 0.8 and 1.9 GeV/c are obtained from a sample of 232×10^6 Υ(4S)→BB̅ events, collected with the BABAR detector at the PEPII asymmetricenergy Bmeson factory at SLAC. We also present a reevaluation of the moments of electronenergy spectra and partial decay fractions B(B̅ →X_ce^ν̅ ) for minimum electron momenta between 0.6 and 1.5 GeV/c based on a sample of 51×10^6 Υ(4S)→BB̅ events. The measurements are used for the extraction of the total decay fraction, the CabibboKobayashiMaskawa (CKM) matrix element V_(cb), the quark masses m_b and m_c, and four heavyquark QCD parameters in the framework of a HeavyQuark Expansion (HQE). We find B(B̅ →X_cℓ^ν̅ )=(10.64±0.17±0.06)% and V_(cb)=(42.05±0.45±0.70)×10^(3). 


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ABSTRACT: We present a study of the $D^+\pi^$, $D^0\pi^+$, and $D^{*+}\pi^$ systems in inclusive $e^+e^ \rightarrow c\bar{c}$ interactions in a search for new excited $D$ meson states. We use a dataset, consisting of $\sim$454 fb$^{1}$, collected at centerofmass energies near 10.58 GeV by the BABAR detector at the SLAC PEPII asymmetricenergy collider. We observe, for the first time, candidates for the radial excitations of the $D^0$, $D^{*0}$, and $D^{*+}$, as well as the $L=2$ excited states of the $D^0$ and $D^+$, where $L$ is the orbital angular momentum of the quarks. 
Article: Observation of the $\Upsilon(1^3D_J)$ Bottomonium State through Decays to $\pi^+\pi^\Upsilon(1S)$
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ABSTRACT: Based on $122\times 10^6$ \ThreeS events collected with the \babar\ detector, we have observed the \OneDJ bottomonium state through the $\ThreeS\to\g\g\OneDJ\to\g\g\pip\pim\OneS$ decay chain. The significance is 6.2 standard deviations including systematic uncertainties. The mass of the J=2 member of the \OneDJ triplet is determined to be $10164.5\pm0.8 \rm{(stat.)}\pm0.5 \rm{(syst.)}$ \mevcc. We use the $\pip\pim$ invariant mass and decay angular distributions to confirm the consistency of the observed state with the orbital angular momentum and parity assignments of the \OneDJ. 
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ABSTRACT: We report the observation of the decay $B^{} \rightarrow D^{(*)+}_{s} K^{} \ell^{} \bar{\nu}_{\ell}$ based on $342 \mathrm {\,fb}^{1}}$ of data collected at the $\Y4S$ resonance with the BABAR detector at the PEPII $e^{+}e^{}$ storage rings at SLAC. A simultaneous fit to three $D^{+}_{s}$ decay chains is performed to extract the signal yield from measurements of the squared missing mass in the B meson decay. We observe the decay $B^{} \rightarrow D^{(*)+}_{s} K^{} \ell^{} \bar{\nu}_{\ell}$ with a significance greater than five standard deviations (including systematic uncertainties) and measure its branching fraction to be $\BR(B^{} \rightarrow D^{(*)+}_{s} K^{} \ell^{} \bar{\nu}_{\ell}) = [6.13^{+1.04}_{1.03}(\mathrm{stat.})\pm0.43(\mathrm{syst.}) \pm 0.51(\BR(D_{s}))]\times10^{4}$, where the last error reflects the limited knowledge of the $D_{s}$ branching fractions. 
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ABSTRACT: Using 347.5 fb1 of data recorded by the BABAR detector at the PEPII electronpositron collider, 244*10^3 signal events for the D+ > K pi+ e+ nu_e decay channel are analyzed. This decay mode is dominated by the \bar{K}^*(892)^0 contribution. We determine the \bar{K}^*(892)^0 parameters: m_{K^*(892)^0}=(895.4 + 0.2 + 0.2) MeV/c^{2}, \Gamma^0_{K^*(892)^0}=(46.5 + 0.3 + 0.2) MeV/c^{2} and the BlattWeisskopf parameter $r_{BW}=2.1 + 0.5 + 0.5 (GeV/c)^{1} where the first uncertainty comes from statistics and the second from systematic uncertainties. We also measure the parameters defining the corresponding hadronic form factors at q^{2}=0 (r_{V} = V(0) / A_{1}(0)=1.463 + 0.017 + 0.031, r_{2} = A_{2}(0) / A_{1}(0) = 0.801 + 0.020 + 0.020) and the value of the axialvector pole mass parameterizing the q^2 variation of A_{1} and A_{2}: m_{A}=(2.63 + 0.10 + 0.13) GeV/c^{2}. The Swave fraction is equal to (5.79 + 0.16 + 0.15)%. Other signal components correspond to fractions below 1%. Using the D+ > K pi+ pi+ channel as a normalization, we measure the D+ semileptonic branching fraction: BR(D+ > K pi+ e+ nu_e) = (4.04 + 0.03 + 0.04 + 0.09) \times 10^{2} where the third uncertainty comes from external inputs. We then obtain the value of the hadronic form factor A_1 at q^{2}=0: A_{1}(0) = 0.6226 + 0.0056 + 0.0065 + 0.0074. Fixing the Pwave parameters we measure the phase of the Swave for several values of the Kpi mass. These results confirm those obtained with Kpi production at small momentum transfer in fixed target experiments. 

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ABSTRACT: We present an analysis of exclusive charmless semileptonic Bmeson decays based on 377 million BBbar pairs recorded with the BABAR detector at the Upsilon(4S) resonance. We select four event samples corresponding to the decay modes B0 > pi l+ nu, B+ > pi0 l+ nu, B0 > rho l+ nu, and B+ > rho0 l+ nu, and find the measured branching fractions to be consistent with isospin symmetry. Assuming isospin symmetry, we combine the two pi l nu samples, and similarly the two rho l nu samples, and measure the branching fractions BF(B0 > pi l+ nu) = (1.41 + 0.05 + 0.07) x 10^4 and BF(B0 > rho l+ nu) = (1.75 + 0.15 + 0.27) x 10^4, where the errors are statistical and systematic. We compare the measured distribution in q^2, the momentum transfer squared, with predictions for the form factors from lattice QCD calculations and lightcone sum rules, and determine the CKM matrix element V_ub. From a simultaneous fit to B > pi l nu data and FNAL/MILC lattice QCD results, we obtain V_ub = (2.95 + 0.31) x 10^3 from B > pi l nu, where the uncertainty is the combined experimental and theoretical error. 


Article: Observation of eta_c(1S) and eta_c(2S) decays to K+ K pi+ pi pi0 in twophoton interactions
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ABSTRACT: We study the processes gamma gamma > K^0_S K+/ pi/+ and gamma gamma > K+ K pi+ pi pi0 using a data sample of 519.2 fb1 recorded by the BaBar detector at the PEPII asymmetricenergy e+e collider at centerofmass energies near the Upsilon(nS) (n = 2,3,4) resonances. We observe the eta_c(1S), chi_c0(1P), chi_c2(1P), and eta_c(2S) resonances produced in twophoton interactions and decaying to K+ K pi+ pi pi0, with significances of 18.1, 5.7, 5.2, and 5.3 standard deviations (including systematic errors), respectively. We measure the eta_c(2S) mass and width in K^0_S K+/ pi/+ decays, m(eta_c(2S))=3638.5 +/ 1.5 +/ 0.8 MeV/c^2 and Gamma(eta_c(2S)) = 13.4 +/ 4.6 +/ 3.2 MeV, where the first uncertainty is statistical and the second is systematic. We search for the Z(3930) resonance and find no significant signal. We also provide the twophoton width times branching fraction values for the observed resonances. 
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ABSTRACT: The decay width and mass of the Ds1(2536)+ meson are measured via the decay channel Ds1+ > D*+KS0 using 385 fb^1 of data recorded with the BABAR detector in the vicinity of the Y(4S) resonance at the PEPII asymmetricenergy electronpositron collider. The result for the decay width is 0.92 + 0.03 (stat) + 0.04 (syst) MeV. For the mass, a value of 2535.08 + 0.01 + 0.15 MeV/c^2 is obtained. The mass difference between the Ds1+ and the D*+ is measured to be 524.83 + 0.01 + 0.04 MeV/c^2, representing a significant improvement compared to the current world average. The unnatural spinparity assignment for the Ds1+ meson is confirmed. 



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ABSTRACT: Production and decay of Î©{sub c}Â° baryons is studied with â 230 fbâ»Â¹ of data recorded with the BABAR detector at the PEPII e{sup +}eâ» asymmetricenergy storage ring at SLAC. The Î©{sub c}Â° is reconstructed through its decays into Î©â»Ï{sup +}, Î©â»Ï{sup +}Ïâ»Ï{sup +}, Îâ»Kâ»Ï{sup +}Ï{sup +} final states. The invariant mass spectra are presented and the signal yields are extracted. Ratios of branching fractions are measured relative to the Î©{sub c}Â° â Î©â»Ï{sup +} mode Î(Î©{sub c}Â° â Îâ» Kâ»Ï{sup +}Ï{sup +})/Î(Î©{sub c}Â° â Î©â»Ï{sup +}) = 0.31 {+} 0.15(stat.) {+} 0.04(syst.), Î(Î©{sub c}Â° â Î©â» Ï{sup +}Ïâ»Ï{sup +})/Î(Î©{sub c}Â° â Î©â»Ï{sup +}) < 0.30 (90%CL). The momentum spectrum (not corrected for efficiency) of Î©{sub c}Â° baryons is extracted from decays into Î©â»Ï{sup +}, establishing the first observation of Î©{sub c}Â° production from B decays. 

Publication Stats
2k  Citations  
1,676.16  Total Impact Points  
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Institutions

2007

Université de Savoie
Chambéry, RhôneAlpes, France
