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A Measurement of the Semileptonic Branching Fraction of the B_s Meson

Description: We report a measurement of the inclusive semileptonic branching fraction of the B{sub s} meson using data collected with the BABAR detector in the center-of-mass energy region above the {gamma}(4S) resonance. We use the inclusive yield of {phi} mesons and the {phi} yield in association with a high-momentum lepton to perform a simultaneous measurement of the semileptonic branching fraction and the production rate of B{sub s} mesons relative to all B mesons as a function of center-of-mass energy. The inclusive semileptonic branching fraction of the B{sub s} meson is determined to be {Beta}(B{sub s} {yields} {ell}{nu}X) = 9.5{sub -2.0}{sup +2.5}(stat){sub -1.9}{sup +1.1}(syst)%, where {ell} indicates the average of e and {mu}.
Date: June 12, 2012
Creator: Lees, J.P.; Poireau, V.; Tisserand, V.; Garra Tico, J.; Grauges, E.; Martinelli, M. et al.
Partner: UNT Libraries Government Documents Department

Studies of the Performance of the ATLAS Detector Using Cosmic-Ray Muons

Description: Abstract Not Provided
Date: June 12, 2013
Creator: Aad, G. & /Freiburg U. /Oklahoma U. /Barcelona, IFAE /Geneva U. /Oxford U. /Wedel, Fachhochsch. /Oklahoma State U. /Michigan State U. /Tel Aviv U. /Orsay, LAL /INFN, Udine /Brookhaven /Hampton U. /Yale U. /Munich U. /Queen Mary, U. of London /Rutherford /Brandeis U. /Mainz U., Inst. Phys. /Boston U. /SUNY, Stony Brook
Partner: UNT Libraries Government Documents Department

Search for High-Mass States with One Lepton Plus Missing Transverse Momentum in Proton-Proton Collisions at $\sqrt{s} with the ATLAS Detector

Description: The ATLAS detector is used to search for high-mass states, such as heavy charged gauge bosons (W{prime},W*), decaying to a charged lepton (electron or muon) and a neutrino. Results are presented based on the analysis of ppcollisions at a center-of-mass energy of 7 TeV corresponding to an integrated luminosity of 36 pb{sup -1}. No excess beyond standard model expectations is observed. A W{prime} with sequential standard model couplings is excluded at 95% confidence level for masses below 1.49 TeV, and a W* (charged chiral boson) for masses below 1.35 TeV.
Date: June 20, 2012
Creator: Aad, Georges; Abbott, Brad; Abdallah, Jalal; Abdelalim, Ahmed Ali; Abdesselam, Abdelouahab; Abdinov, Ovsat et al.
Partner: UNT Libraries Government Documents Department

Observation of e^+e^- to \rho^+\rho^- near \sqrt{s}=10.58\gev

Description: The authors report the first observation of e{sup +}e{sup -} {yields} {rho}{sup +}{rho}{sup -}, in a data sample of 379 fb{sup -1} collected with the BABAR detector at the PEP-II e{sup +}e{sup -} storage ring at center-of-mass energies near {radical}s = 10.58 GeV. The authors measure a cross section of {sigma}(e{sup +}e{sup -} {yields} {rho}{sup +}{rho}{sup -}) = 19.5 {+-} 1.6(stat) {+-} 3.2(syst) fb. Assuming production through single-photon annihilation, there are three independent helicity amplitudes. They measure the ratios of their squared moduli to be |F{sub 00}|{sup 2} : |F{sub 10}|{sup 2} : |F{sub 11}|{sup 2} = 0.51 {+-} 0.14(stat) {+-} 0.07(syst) : 0.10 {+-} 0.04(stat) {+-} 0.01(syst) : 0.04 {+-} 0.03(stat) {+-} 0.01(syst). The |F{sub 00}|{sup 2} result is inconsistent with the prediction of 1.0 made by QCD models with a significance of 3.1 standard deviations including systematic uncertainties.
Date: June 26, 2008
Creator: Aubert, B.; Bona, M.; Karyotakis, Y.; Lees, J.P.; Poireau, V.; Prencipe, E. et al.
Partner: UNT Libraries Government Documents Department

A Search for the Rare Decay $B\rightarrow\gamma\gamma$

Description: We report the result of a search for the rare decay B{sup 0} {yields} {gamma}{gamma} in 426 fb{sup -1} of data, corresponding to 226 million B{sup 0}{bar B}{sup 0} pairs, collected on the {Upsilon}(4S) resonance at the PEP-II asymmetric-energy e{sup +}e{sup -} collider using the BABAR detector. We use a maximum likelihood fit to extract the signal yield and observe 21{sub -12}{sup +13} signal events with a statistical signficance of 1.9 {sigma}. This corresponds to a branching fraction {Beta}(B{sup 0} {yields} {gamma}{gamma}) = (1.7 {+-} 1.1(stat.) {+-} 0.2(syst.)) x 10{sup -7}. Based on this result, we set a 90% confidence level upper limit of {Beta}(B{sup 0} {yields} {gamma}{gamma}) < 3.2 x 10{sup -7}.
Date: June 2, 2011
Creator: del Amo Sanchez, P.; Lees, J.P.; Poireau, V.; Prencipe, E.; Tisserand, V.; /Annecy, LAPP et al.
Partner: UNT Libraries Government Documents Department

Searches for the baryon- and lepton-number violating decays $B^0\rightarrow\Lambda_c^ \ell^-$, $B^-\rightarrow\Lambda\ell^-$, and $B^-\rightarrow\bar{\Lambda}\ell^-$

Description: Searches for B mesons decaying to final states containing a baryon and a lepton are performed, where the baryon is either {Lambda}{sub c} or {Lambda} and the lepton is a muon or an electron. These decays violate both baryon and lepton number and would be a signature of physics beyond the standard model. No significant signal is observed in any of the decay modes, and upper limits in the range (3.2 - 520) x 10{sup -8} are set on the branching fractions at the 90% confidence level.
Date: June 22, 2011
Creator: del Amo Sanchez, P.; Lees, J.P.; Poireau, V.; Prencipe, E.; Tisserand, V.; /Annecy, LAPP et al.
Partner: UNT Libraries Government Documents Department

Measurements of B to {pi, eta, eta'} l nu Branching Fractions andDetermination of |Vub| with Semileptonically Tagged B Mesons

Description: The authors report measurements of branching fractions for the decays B {yields} P{ell}{nu}{sub {ell}}, where P are the pseudoscalar charmless mesons {pi}{sup -}, {pi}{sup 0}, {eta} and {eta}{prime}, based on 348 fb{sup -1} of data collected with the BABAR detector, using B{sup 0} and B{sup +} mesons found in the recoil of a second B meson decaying as B {yields} D{sup (*)}{ell}{nu}{sub {ell}}. Assuming isospin symmetry, they combine pionic branching fractions to obtain {Beta}(B{sup 0} {yields} {pi}{sup -} {ell}{sup +} {nu}{sub {ell}}) = (1.54 {+-} 0.17{sub (stat)} {+-} 0.09{sub (syst)}) x 10{sup -4}; they find 3.2{sigma} evidence of the decay B{sup +} {yields} {eta}{ell}{sup +}{nu}{sub {ell}} and measure its branching fraction to be (0.64 {+-} 0.20{sub (stat)} {+-} 0.3{sub (syst)}) x 10{sup -4}, and determine {Beta}(B{sup +} {yields} {eta}{prime}{ell}{sup +}{nu}{sub {ell}}) < 0.47 x 10{sup -4} to 90% confidence level. Using partial branching fractions for the pionic decays in ranges of the momentum transfer and a recent form factor calculation, they obtain the magnitude of the Cabibbo-Kobayashi-Maskawa matrix element |V{sub ub}| = (4.0 {+-} 0.5{sub (stat)} {+-} 0.2{sub (syst){sub -0.5}{sup +0.7}(theory)}) x 10{sup -3}.
Date: June 2, 2008
Creator: Aubert, B.; Bona, M.; Karyotakis, Y.; Lees, J.P.; Poireau, V.; Prencipe, E. et al.
Partner: UNT Libraries Government Documents Department

Measurement of |Vcb| and the Form-Factor Slope in Bbar -> Dlnu Decays in Events Tagged by a Fully Reconstructed B Meson

Description: We present a measurement of the Cabibbo-Kobayashi-Maskawa matrix element |V{sub cb}| and the form-factor slope {rho}{sup 2} in {bar B} {yields} D{ell}{sup -} {bar {nu}}{sub {ell}} decays based on 460 million B{bar B} events recorded at the {Gamma}(4S) resonance with the BABAR detector. {bar B} {yields} D{ell}{sup -} {bar {nu}}{sub {ell}} decays are selected in events in which a hadronic decay of the second B meson is fully reconstructed. We measure the differential decay rate and determine G(1)|V{sub cb}| = (43.0 {+-} 1.9 {+-} 1.4) x 10{sup -3} and {rho}{sup 2} = 1.20 {+-}0.09 {+-} 0.04, where G(1) is the hadronic form factor at the point of zero recoil. We also determine the exclusive branching fractions and find {Beta}(B{sup -} {yields} D{sup 0} {ell}{sup -}{bar {nu}}{sub {ell}}) = (2.31 {+-} 0.08 {+-} 0.09)% and {Beta}(B{sup 0} {yields} D{sup +} {ell}{sup -} {bar {nu}}{sub {ell}}) = (2.23 {+-} 0.11 {+-} 0.11)%.
Date: June 30, 2011
Creator: Aubert, Bernard; Karyotakis, Y.; Lees, J.P.; Poireau, V.; Prencipe, E.; Prudent, X. et al.
Partner: UNT Libraries Government Documents Department

Measurements of Charged Current Lepton Universality and |Vus| using Tau Lepton Decays to e- v v, __- v v, pi- v and K- v

Description: Using 467 fb{sup -1} of e{sup +}e{sup -} annihilation data collected with the BABAR detector, they measure {Beta}({tau}{sup -} {yields} {mu}{sup -}{bar {nu}}{sub {mu}}{nu}{sub {tau}})/{Beta}({tau}{sup -} {yields} e{sup -} {bar {nu}}{sub e}{nu}{sub {tau}}) = (0.9796 {+-} 0.0016 {+-} 0.0036), {Beta}({tau}{sup -} {yields} {pi}{sup -} {nu}{sub {tau}})/{Beta}({tau}{sup -} {yields} e{sup -}{bar {nu}}{sub e}{nu}{sub {tau}}) = (0.5945 {+-} 0.0014 {+-} 0.0061), and {Beta}({tau}{sup -} {yields} K{sup -}{nu}{sub {tau}})/{Beta}({tau}{sup -} {yields} e{sup -}{bar {nu}}{sub e}{nu}{sub {tau}}) = (0.03882 {+-} 0.00032 {+-} 0.00057), where the uncertainties are statistical and systematic, respectively. From these precision {tau} measurements, they test the Standard Model assumption of {mu}-e and {tau}-{mu} charge current lepton universality and provide determinations of |V{sub us}| experimentally independent of the decay of a kaon.
Date: June 30, 2011
Creator: Aubert, Bernard; Karyotakis, Y.; Lees, J.P.; Poireau, V.; Prencipe, E.; Prudent, X. et al.
Partner: UNT Libraries Government Documents Department

Combined Phase SpaceCharacterization at the PEP-II IP using Single-beam and Luminous-region Measurements

Description: We present a novel method to characterize the e{sup {+-}} phase space at the IP of the SLAC B-factory, that combines single-beam measurements with a detailed mapping of luminous-region observables. Transverse spot sizes are determined in the two rings with synchrotron-light monitors and extrapolated to the IP using measured lattice functions. The specific luminosity, which is proportional to the inverse product of the overlap IP beam sizes, is continuously monitored using radiative/Bhabha events. The spatial variation of the luminosity and of the transverse-boost distribution of the colliding e{sup {+-}}, are measured using e{sup +}e{sup -} {yields} {mu}{sup +}{mu}{sup -} events reconstructed in the BABAR detector. The combination of these measurements provide constraints on the emittances, horizontal and vertical spot sizes, angular divergences and {beta} functions of both beams at the IP during physics data-taking. Preliminary results of this combined spot-size analysis are confronted with independent measurements of IP {beta}-functions and overlap IP beam sizes at low beam current.
Date: June 23, 2006
Creator: Bevan, A.; /Queen Mary, U. of London; Kozanecki, W.; /Saclay; Viaud, B.; U., /Montreal et al.
Partner: UNT Libraries Government Documents Department

Evidence for B+ -> K*0bar K*+

Description: We present measurements of the branching fraction and fraction of longitudinal polarization for the decay B{sup +} {yields} {bar K}*{sup 0} K*{sup +} with a sample of 467 {+-} 5 million B{bar B} pairs collected with the BABAR detector at the PEP-II asymmetric-energy e{sup +}e{sup -} collider at the SLAC National Accelerator Laboratory. We obtain the branching fraction {Beta}(B{sup +} {yields} {bar K}*{sup 0} K*{sup +}) = (1.2 {+-} 0.5 {+-} 0.1) x 10{sup ?6} with a significance of 3.7 standard deviations including systematic uncertainties. We measure the fraction of longitudinal polarization f{sub L} = 0.75{sub -0.26}{sup +0.16} {+-} 0.03. The first error quoted is statistical and the second is systematic.
Date: June 19, 2009
Creator: Aubert, B.; Bona, M.; Karyotakis, Y.; Lees, J.P.; Poireau, V.; Prencipe, E. et al.
Partner: UNT Libraries Government Documents Department

Exclusive Initial-State-Radiation Production of the DDbar,D*Dbar, and D*D*bar Systems

Description: We perform a study of the exclusive production of D{bar D}, D*{bar D}, and D*{bar D}* in initial-state-radiation events, from e{sup +}e{sup -} annihilations at a center-of-mass energy near 10.58 GeV, to search for charmonium and possible new resonances. The data sample corresponds to an integrated luminosity of 384 fb{sup -1} and was recorded by the BABAR experiment at the PEP-II storage rings. The D{bar D}, D*{bar D}, and D*{bar D}* mass spectra show clear evidence of several {psi} resonances. However, there is no evidence for Y(4260) {yields} D*{bar D} or Y(4260) {yields} D*{bar D}*.
Date: June 19, 2009
Creator: Aubert, B.; Karyotakis, Y.; Lees, J.P.; Poireau, V.; Prencipe, E.; Prudent, X. et al.
Partner: UNT Libraries Government Documents Department

Search for the Rare Leptonic Decays B^+ \to l^+ \nu_l (l=e,\mu)

Description: We have performed a search for the rare leptonic decays B{sup +} {yields} {ell}{sup +} {nu}{sub {ell}}({ell} = e,{mu}), using data collected at the ?(4S) resonance by the BABAR detector at the PEP-II storage ring. In a sample of 468 x 10{sup 6} B{bar B} pairs we find no evidence for a signal and set an upper limit on the branching fractions B(B{sup +} {yields} e{sup +}{nu}{sub e}) < 1.9 x 10{sup -6} at the 90% confidence level, using a Bayesian approach.
Date: June 19, 2009
Creator: Aubert, B.; Karyotakis, Y.; Lees, J.P.; Poireau, V.; Prencipe, E.; Prudent, X. et al.
Partner: UNT Libraries Government Documents Department

Measurement of the e^+e^-\to b\bar{b} cross section between \SqrtS=10.54 and 11.20 \gev

Description: We report e{sup +}e{sup -} {yields} b{bar b} cross section measurements by the BABAR experiment performed during an energy scan in the range of 10.54 to 11.20 GeV at the PEP-II e{sup +}e{sup -} collider. A total relative error of about 5% is reached in more than three hundred center-of-mass energy steps, separated by about 5MeV. These measurements can be used to derive precise information on the parameters of the {Upsilon}(10860) and {Upsilon}(11020) resonances. In particular we show that their widths may be smaller than previously measured.
Date: June 19, 2009
Creator: Aubert, B.; Bona, M.; Karyotakis, Y.; Lees, J.P.; Poireau, V.; Prencipe, E. et al.
Partner: UNT Libraries Government Documents Department

Improved Limits on the Lepton Flavor Violating Decays Tau -> l V^0

Description: The authors search for the neutrinoless, lepton-flavor-violating tau decays {tau}{sup -} {yields} {ell}{sup -}V{sup 0}, where {ell} is an electron or muon and V{sup 0} is a fector meson reconstructed as {phi} {yields} K{sup +}K{sup -}, {rho} {yields} {pi}{sup +}{pi}{sup -}, K* {yields} K{sup +}{pi}{sup -}, {bar K}* {yields} K{sup -}{pi}{sup +}. The analysis has been performed using 451 fb{sup -1} of data collected at an e{sup +}e{sup -} center-of-mass energy near 10.58 GeV with the BABAR detector at the PEP-II storage rings. The number of events found in the data is compatible with the background expectation, and upper limits on the branching fractions are set in the range (2.6-19) x 10{sup -8} at the 90% confidence level.
Date: June 19, 2009
Creator: Aubert, B.; Karyotakis, Y.; Lees, J.P.; Poireau, V.; Prencipe, E.; Prudent, X. et al.
Partner: UNT Libraries Government Documents Department

Measurement of CP Asymmetries and Branching Fractions in Charmless Two-Body B-Meson Decays to Pions and Kaons

Description: We present improved measurements of CP-violation parameters in the decays B{sup 0} {yields} {pi}{sup +}{pi}{sup -}, B{sup 0} {yields} K{sup +}{pi}{sup -}, and B{sup 0} {yields} {pi}{sup 0}{pi}{sup 0}, and of the branching fractions for B{sup 0} {yields} {pi}{sup 0}{pi}{sup 0} and B{sup 0} {yields} K{sup 0}{pi}{sup 0}. The results are obtained with the full data set collected at the {Upsilon}(4S) resonance by the BABAR experiment at the PEP-II asymmetric-energy B factory at the SLAC National Accelerator Laboratory, corresponding to 467 {+-} 5 million B{bar B} pairs. We find the CP-violation parameter values and branching fractions S{sub {pi}{sup +}{pi}{sup -}} = -0.68 {+-} 0.10 {+-} 0.03, C{sub {pi}{sup +}{pi}{sup -}} = -0.25 {+-} 0.08 {+-} 0.02, {Alpha}{sub K{sup -}{pi}{sup +}} = -0.107 {+-} 0.016{sub -0.004}{sup +0.006}, C{sub {pi}{sup 0}{pi}{sup 0}} = -0.43 {+-} 0.26 {+-} 0.05, {Beta}(B{sup 0} {yields} {pi}{sup 0}{pi}{sup 0}) = (1.83 {+-} 0.21 {+-} 0.13) x 10{sup -6}, {Beta}(B{sup 0} {yields} K0{pi}{sup 0}) = (10.1 {+-} 0.6 {+-} 0.4) x 10{sup -6}, where in each case, the first uncertainties are statistical and the second are systematic. We observe CP violation with a significance of 6.7 standard deviations for B{sup 0} {yields} {pi}{sup +}{pi}{sup -} and 6.1 standard deviations for B{sup 0} {yields} K{sup +}{pi}{sup -}, including systematic uncertainties. Constraints on the Unitarity Triangle angle {alpha} are determined from the isospin relations among the B {yields} {pi}{pi} rates and asymmetries. Considering only the solution preferred by the Standard Model, we find {alpha} to be in the range [71{sup o}, 109{sup o}] at the 68% confidence level.
Date: June 18, 2012
Creator: Lees, J. P.; Poireau, V.; Tisserand, V.; /Annecy, LAPP; Garra Tico, J.; Grauges, E. et al.
Partner: UNT Libraries Government Documents Department

Searches for Lepton Flavor Violation in the Decays tau+- ---> e+- gamma and tau+- ---> mu+- gamma

Description: Searches for lepton-flavor-violating decays of a {tau} lepton to a lighter mass lepton and a photon have been performed with the entire dataset of (963 {+-} 7) x 10{sup 6} {tau} decays collected by the BABAR detector near the {Upsilon}(4S), {Upsilon}(3S) and {Upsilon}(2S) resonances. The searches yield no evidence of signals and they set upper limits on the branching fractions of {Beta}({tau}{sup {+-}} {yields} e{sup {+-}}{gamma}) < 3.3 x 10{sup -8} and {Beta}({tau}{sup {+-}} {yields} {mu}{sup {+-}}{gamma}) < 4.4 x 10{sup -8} at 90% confidence level.
Date: June 11, 2010
Creator: Aubert, Bernard; Karyotakis, Y.; Lees, J.P.; Poireau, V.; Prencipe, E.; Prudent, X. et al.
Partner: UNT Libraries Government Documents Department

Test of Lepton Universality in Upsilon(1S) Decays at BaBar

Description: The ratio R{sub {tau}{mu}}({Upsilon}(1S))={Lambda}{sub {Upsilon}(1S){yields}{tau}{sup +}{tau}{sup -}}/{Lambda}{sub {Upsilon}(1S){yields}{mu}{sup +}{mu}{sup -}} is measured using a sample of (121.8 {+-} 1.2) x 10{sup 6}{Upsilon}(3S) events recorded by the BABAR detector. This measurement is intended as a test of lepton universality and as a search for a possible light pseudoscalar Higgs boson. In the standard model (SM) this ratio is expected to be close to 1. Any significant deviations would violate lepton universality and could be introduced by the coupling to a light pseudoscalar Higgs boson. The analysis studies the decays {Upsilon}(3S) {yields} {Upsilon}(1S){sub {pi}{sup +}{pi}{sup -}}, {Upsilon}(1S) {yields} {ell}{sup +}{ell}{sup -}, where l = {mu}, {tau}. The result, R{sub {tau}{mu}}({Upsilon}(1S))=1.005 {+-} 0.013(stat) {+-} 0.022(syst), shows no deviation from the expected SM value, while improving the precision with respect to previous measurements.
Date: June 7, 2010
Creator: del Amo Sanchez, P.; Lees, J.P.; Poireau, V.; Prencipe, E.; Tisserand, V.; /Annecy, LAPP et al.
Partner: UNT Libraries Government Documents Department

Measurement of the Branching Fraction for D8+ rarr tau+nu_tau and Extraction of the Decay Constant f_D_s

Description: The branching fraction for the decay D{sub s}{sup +} {yields} {tau}{sup +}{nu}{sub {tau}} with {tau}{sup +} {yields} e{sup +}{bar {nu}}{sub {tau}}, is measured using a data sample corresponding to an integrated luminosity of 427 fb{sup -1} collected at center of mass energies near 10.58 GeV with the BABAR detector at the PEP-II asymmetric-energy e{sup +}e{sup -} collider at SLAC. In the process e{sup +}e{sup -} {yields} c{bar c} {yields} D*{sub s}{sup +} {bar D}{sub TAG}{bar K}X, the D*{sub s}{sup +} meson is reconstructed as a missing particle, and the subsequent decay D*{sub s}{sup +} {yields} D{sub s}{sup +}{gamma} yields an inclusive D{sub s}{sup +} data sample. Here {bar D}{sub TAG} refers to a fully reconstructed hadronic {bar D} decay, {bar K} is a K{sup -} or {bar K}{sup 0}, and X stands for any number of charged or neutral pions. The decay D{sub s}{sup +} {yields} K{sub S}{sup 0}K{sup +} is isolated also, and from ratio of event yields and known branching fractions, {Beta}(D{sub s}{sup +} {yields} {tau}{sup +}{nu}{sub {tau}}) = (4.5 {+-} 0.5 {+-} 0.4 {+-} 0.3)% is determined. The pseudoscalar decay constant is extracted to be f{sub D{sub s}} = (233 {+-} 13 {+-} 10 {+-} 7) MeV, where the first uncertainty is statistical, the second is systematic, and the third results from the uncertainties on the external measurements used as input to the calculation.
Date: June 4, 2010
Creator: Lees, J.P.; Poireau, V.; Prencipe, E.; Tisserand, V.; /Annecy, LAPP; Garra Tico, J. et al.
Partner: UNT Libraries Government Documents Department

Observation of the Rare Decay B^+ to K^+ \pi^0 \pi^0

Description: We report an analysis of charmless hadronic decays of charged B mesons to the final state K{sup +}{pi}{sup 0}{pi}{sup 0}, using a data sample of 470.9 {+-} 2.8 million B{bar B} events collected with the BABAR detector at the {Upsilon}(4S) resonance. We observe an excess of signal events with a significance above 10 standard deviations including systematic uncertainties and measure the branching fraction to be {Beta}(B{sup +}{yields}K{sup +}{pi}{sup 0}{pi}{sup 0}) = (15.5 {+-} 1.1 {+-} 1.6) x 10{sup -6}, where the uncertainties are statistical and systematic, respectively.
Date: June 11, 2010
Creator: del Amo Sanchez, P.; Lees, J.P.; Poireau, V.; Prencipe, E.; Tisserand, V.; /Annecy, LAPP et al.
Partner: UNT Libraries Government Documents Department

Observation of the Upsilon(13DJ ) Bottomonium State through Decays to pi+pi-Upsilon(1S)

Description: Based on 122X10{sup 6} {upsilon}(3S) events collected with the BABAR detector, we have observed the {upsilon}(1{sup 3}D{sub J}) bottomonium state through the {upsilon}(3S){yields}{gamma}{gamma}{upsilon}(1{sup 3}D{sub J}){yields}{gamma}{gamma}{pi}{sub +}{pi}{sub -}{upsilon}(1S) decay chain. The significance is 6.2 standard deviations including systematic uncertainties. The mass of the J = 2 member of the {upsilon}(1{sup 3}D{sub J}) triplet is determined to be 10164.5{-+}0.8 (stat.) {-+} 0.5 (syst.) MeV/c{sup 2}. We use the {pi}{sup +}{pi}{sup -} invariant mass and decay angular distributions to confirm the consistency of the observed state with the orbital angular momentum and parity assignments of the {upsilon}(1{sup 3}D{sub J}).
Date: June 2, 2010
Creator: del Amo Sanchez, P.; Lees, J.P.; Poireau, V.; Prencipe, E.; Tisserand, V.; /Annecy, LAPP et al.
Partner: UNT Libraries Government Documents Department

Search for B-meson decays to b1rho and b1K___

Description: We present a search for decays of B mesons to final states with a b{sub 1} meson and a {rho} or K*(892) meson. The search is based on a data sample consisting of 465 million B{bar B} pairs collected by the BABAR detector at the SLAC National Accelerator Laboratory. We do not observe any statistically significant signal. The upper limits we set on the branching fractions range from 1.4 to 8.0 x 10{sup -6} at the 90% confidence level (C.L.), including systematic uncertainties.
Date: June 11, 2010
Creator: Aubert, Bernard; Karyotakis, Y.; Lees, J.P.; Poireau, V.; Prencipe, E.; Prudent, X. et al.
Partner: UNT Libraries Government Documents Department

Search for the B to K nu nu-bar Decay Using Semi-Leptonic Tags

Description: We present an update of the search for the flavor-changing neutral current B{sup +} {yields} K{sup +}{nu}{bar {nu}} decay using 351 X 10{sup 6} B{bar B} pairs collected at the {Upsilon}(4S) resonance with the BABAR detector at the SLAC PEP-II B factory. Due to the presence of two neutrinos in the final state, we require the reconstruction of the companion B in the event through the decay channel B{sup -} {yields} D{sup 0}{ell}{sup -}{bar {nu}}X. We find 38 candidates in the data with an expected background of 31{-+} 12. This allows us to set an upper limit on the branching fraction for B{sup +} {yields} K{sup +}{nu}{bar {nu}} of 4.5 X 10{sup -5} at 90% confidence level.
Date: June 2, 2010
Creator: Aubert, B.; Karyotakis, Y.; Lees, J.P.; Poireau, V.; Prencipe, E.; Prudent, X. et al.
Partner: UNT Libraries Government Documents Department