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Measurement of the Moments of the Hadronic Invariant Mass Distribution in Semileptonic Beta Decays

Description: Using 180 pb{sup -1} of data collected with the CDF II detector at the Tevatron, we measure the first two moments of the hadronic invariant mass-squared distribution in charmed semileptonic B decays. From these we determine the non-perturbative Heavy Quark Effective Theory parameters {Lambda} and {lambda}{sub 1} used to relate the B meson semileptonic branching ratio to the CKM matrix element |V{sub cb}|.
Date: March 13, 2005
Creator: Acosta, D. & TITLE=Measuremen, The CDF Collaboration
Partner: UNT Libraries Government Documents Department

Unitarity Triangle Angle Measurements at BaBar

Description: We present recent results of measurements of the Unitarity Triangle angles alpha, beta and gamma made with the BaBar detector at the PEP-II asymmetric B factory. We present recent results of measurements of the Unitarity Triangle angles alpha, beta and gamma made with the BaBar detector at the PEP-II asymmetric B factory.
Date: June 30, 2005
Creator: Latham, Thomas E.
Partner: UNT Libraries Government Documents Department

Dalitz Plot Analyses of Charmless B Decays

Description: We present preliminary results of maximum-likelihood Dalitz plot analyses performed by the BABAR Collaboration of the charmless hadronic decays B{sup 0} {yields} K{sup +}{pi}{sup -}{pi}{sup 0}, B{sup +} {yields} K{sup +}{pi}{sup -}{pi}{sup +}, and B{sup +} {yields} {pi}{sup +}{pi}{sup -}{pi}{sup +}. We report inclusive decay rates, as well as fractions and phases for intermediate resonant decays.We also report CP-violating charge asymmetries for intermediate resonant decays of neutral B mesons.
Date: October 26, 2005
Creator: Yu, Z.
Partner: UNT Libraries Government Documents Department

The Measurement of CP Asymmetries And Branching Fractions in Neutral B Meson Decays to Charged Rhos And Pions (Kaons) With the BaBar Detector

Description: The authors present measurements of branching ratios and CP-violating asymmetries for neutral B decays into quasi two-body final states dominated by the modes {rho}{sup {+-}}{pi}{sup {-+}} and {rho}{sup {+-}}K{sup {-+}}. The data set used for these measurements was recorded during the 1999-2002 period, and corresponds to a total integrated luminosity of 81.9 fb{sup -1} taken on the {Upsilon}(4S) peak, and 9.5 fb{sup -1} taken 40 MeV off-peak. From a time-dependent maximum likelihood fit they find for the branching fractions {Beta}({rho}{sup 2}{pi}{sup {-+}}) = (22.6 {+-} 1.8(stat) {+-} 2.2(syst)) x 10{sup -6}, {Beta}({rho}{sup {+-}}K{sup {-+}}) = (7.3{sub -1.2}{sup +1.3}(stat) {+-} 1.3(syst)) x 10{sup -6}. For the CP violation parameters, they measure: {Alpha}{sub CP}{sup pK} = 0.28 {+-} 0.17(stat) {+-} 0.080(syst), {Alpha}{sub CP}{sup pk} = -0.18 {+-} 0.08(stat) {+-} 0.029(syst), C{sub pk} = 0.36 {+-} 0.18(stat) {+-} 0.041(syst), S{sub pt} = 0.19 {+-} 0.24(stat) {+-} 0.031(syst), and for the remaining parameters, required to fully describe the time dependence of the B{sup 0}({bar B}{sup 0} {yields} {rho}{sup {+-}}{pi}{sup {-+}}) decays, they obtain {Delta}C{sub pn} = 0.28{sub -0.19}{sup +0.18}(stat) {+-} 0.043(syst), {Delta}S{sub pk} = 0.15 {+-} 0.25(stat) {+-} 0.025(syst).
Date: September 23, 2005
Creator: Liu, Ran
Partner: UNT Libraries Government Documents Department

Recent Results on the CKM Angle Alpha

Description: The method to measure the CKM angle {alpha} and the modes sensitive to it are discussed. It is shown that the B {yields} {rho}{rho} decays provide the most stringent constraint on {alpha}, which is found to be {alpha} = 96{sup o} {+-} 10{sup o}(stat) {+-} 4{sup o}(syst){+-} 13{sup o}(penguin).
Date: October 18, 2005
Creator: Mihalyi, A.
Partner: UNT Libraries Government Documents Department

Hadron Physics at BaBar

Description: The BaBar experiment at SLAC is designed to measure CP violation in the B meson system, however the very high statistics combined with the different e{sup +} and e{sup -} beam energies, the detector design and the open trigger allow a wide variety of spectroscopic measurements. We are beginning to tap this potential via several production mechanisms. Here we present recent results from initial state radiation, hadronic jets, few body B and D hadron decays, and interactions in the detector material. We also summarize measurements relevant to D{sub s} meson spectroscopy, pentaquarks and charmonium spectroscopy from multiple production mechanisms.
Date: October 26, 2005
Creator: Muller, David
Partner: UNT Libraries Government Documents Department

A Search for B+ ---> tau+ neutrino(tau) recoiling against B- ---> D0 l- anti-nu(l) X

Description: The fundamental pursuit of physics has always been a deeper understanding of nature's workings. In the last fifty years this pursuit has culminated in a view of the universe as a complex tapestry woven from only a few fundamental particles and interactions. This description of the universe, the Standard Model of Particle Physics, has been highly successful at predicting the behavior of these particles and interactions. However, the model leaves many questions unanswered and the hope is that many precise tests of its predictions will yield inconsistencies, windows into new physical principles. The search for processes that are allowed by the Standard Model but inherently rare provides fruitful ground for such a test. The large sample of B mesons available from the PEP-II/BABAR B-factory furnishes an opportunity to test Standard Model predictions via rare B meson decay modes.
Date: May 6, 2005
Creator: Sekula, Stephen Jacob
Partner: UNT Libraries Government Documents Department

Branching Fraction for B+ -> pi0 l+ nu, Measured in Upsilon (4S) -> BBbar Events Tagged by B- -> D0 l- nubar (X) Decays

Description: We report a preliminary branching fraction of (1.80 {+-} 0.37{sub stat.} {+-} 0.23{sub syst.}) x 10{sup -4} for the charmless exclusive semileptonic B{sup +} {yields} {pi}{sup 0}{ell}{sup +}{nu} decay, where {ell} can be either a muon or an electron. This result is based on data corresponding to an integrated luminosity of 81 fb{sup -1} collected at the {Upsilon}(4S) resonance with the BABAR detector. The analysis uses B{bar B} events that are tagged by a B meson reconstructed in the semileptonic B{sup -} {yields} D{sup 0}{ell}{sup -}{bar {nu}}(X) decays, where X can be either a {gamma} or a {pi}{sup 0} from a D* decay.
Date: June 29, 2005
Creator: Aubert, B.; Barate, R.; Boutigny, D.; Couderc, F.; Karyotakis, Y.; Lees, J. P. et al.
Partner: UNT Libraries Government Documents Department

Branching Fraction for B0 -> pi- l+ nu and Determination of |Vub| in Upsilon(4S) -> B0 B0bar Events Tagged by B0bar -> D(*)+ l- nubar

Description: We report preliminary results from a study of the charmless exclusive semileptonic decay B{sup 0} {yields} {pi}{sup -}{ell}{sup +}{nu} based on the data collected at the {Upsilon}(4S) resonance using the BABAR detector at SLAC. The analysis uses events in which the signal B meson recoils against a B meson that has been reconstructed in a semileptonic decay {bar B}{sup 0} {yields} D{sup (*)+}{ell}{sup -}{bar {nu}}. We extract the total branching fraction {Beta}(B{sup 0} {yields} {pi}{sup -}{ell}{sup +}{nu}) = (1.03 {+-} 0.25{sub stat.} {+-} 0.13{sub syst.}) x 10{sup -4} and the partial branching fractions in three bins of q{sup 2}, the invariant mass squared of the lepton-neutrino system. From the partial branching fractions and theoretical predictions for the form factors, we determine the magnitude of the CKM matrix element |V{sub ub}|. We find |V{sub ub}| = (3.3 {+-} 0.4{sub stat.} {+-} 0.2{sub syst.} {sub -0.4}{sup +0.8}FF) x 10{sup -3}, where the last error is due to normalization of the form factor.
Date: June 29, 2005
Creator: Aubert, B.; Barate, R.; Boutigny, D.; Couderc, F.; Karyotakis, Y.; Lees, J. P. et al.
Partner: UNT Libraries Government Documents Department

A Search for the Rare Decay B0 to tau+tau- atBaBar

Description: We present the results of a search for the decay B{sup 0} {yields} {tau}{sup +}{tau}{sup -} in a data sample of (232 {+-} 3) x 10{sup 6} {Upsilon}(4S) {yields} B{bar B} decays using the BABAR detector. Certain extensions of the Standard Model predict measurable levels of this otherwise rare decay. We reconstruct fully one neutral B meson and seek evidence for the signal decay in the rest of the event. We find no evidence for signal events and obtain {Beta}(B{sup 0} {yields} {tau}{sup +}{tau}{sup -}) < 3.2 x 10{sup -3} at the 90% confidence level.
Date: November 9, 2005
Creator: Aubert, B.; Barate, R.; Boutigny, D.; Couderc, F.; Karyotakis, Y.; Lees, J. P. et al.
Partner: UNT Libraries Government Documents Department

A Search for the Decay B+ to tau+ nu_tau

Description: We search for the rare leptonic decay B{sup +} {yields} {tau}{sup +}{nu}{sub {tau}} in a sample of 232 x 10{sup 6} B{bar B} pairs collected with the BABAR detector at the SLAC PEP-II B-Factory. Signal events are selected by examining the properties of the B meson recoiling against the semileptonic decay B{sup -} {yields} D*{sup 0}{ell}{bar {nu}}{sub {ell}}. We find no evidence for a signal and set an upper limit on the branching fraction of {Beta}(B{sup +} {yields} {tau}{sup +} {nu}{sub {tau}}) < 2.8 x 10{sup -4} at the 90% confidence level. We combine this result with a previous, statistically independent BABAR search for B{sup +} {yields} {tau}{sup +} {nu}{sub {tau}} to give an upper limit of {Beta}(B{sup +} {yields} {tau}{sup +} {nu}{sub {tau}}) < 2.6 10{sup -4} at the 90% confidence level.
Date: July 27, 2005
Creator: Aubert, B.; Barate, R.; Boutigny, D.; Couderc, F.; Karyotakis, Y.; Lees, J. P. et al.
Partner: UNT Libraries Government Documents Department

Measurement of Branching Fractions and Mass Spectra of B to K pi pi gamma

Description: The authors present a measurement of the partial branching fractions and mass spectra of the exclusive radiative penguin processes B {yields} K{pi}{pi}{gamma} in the range m{sub K{pi}{pi}} < 1.8 GeV/c{sup 2}. They reconstruct four final states: K{sup +}{pi}{sup -}{pi}{sup +}{gamma}, K{sup +}{pi}{sup -}{pi}{sup 0}{gamma}, K{sub S}{sup 0}{pi}{sup -}{pi}{sup +}{gamma}, and K{sub S}{sup 0}{pi}{sup +}{pi}{sup 0}{gamma}, where K{sub S}{sup 0} {yields} {pi}{sup +}{pi}{sup -}. Using 232 million e{sup +}e{sup -} {yields} B{bar B} events recorded by the BABAR experiment at the PEP-II asymmetric-energy storage ring, they measure the branching fractions {Beta}(B{sup +} {yields} K{sup +}{pi}{sup -}{pi}{sup +}{gamma}) = (2.95 {+-} 0.13(stat.) {+-} 0.20(syst)) x 10{sup -5}, {Beta}(B{sup 0} {yields} K{sup +}{pi}{sup -}{pi}{sup 0}{gamma}) = (4.07 {+-} 0.22(stat.) {+-} 0.31(syst.)) x 10{sup -5}, {Beta}(B{sup 0} {yields} K{sup 0}{pi}{sup +}{pi}{sup -}{gamma}) = (1.85 {+-} 0.21(stat.) {+-} 0.12(syst.)) x 10{sup -5}, and {Beta}(B{sup +} {yields} K{sup 0}{pi}{sup +}{pi}{sup 0}{gamma}) = (4.56 {+-} 0.42(stat.) {+-} 0.31(syst.)) x 10{sup -5}.
Date: July 12, 2005
Creator: Aubert, B.; Barate, R.; Boutigny, D.; Couderc, F.; Karyotakis, Y.; Lees, J. P. et al.
Partner: UNT Libraries Government Documents Department

Measurement of the Branching Fraction of B0 Meson Decay to a_1^+(1260) pi-

Description: We present a preliminary measurement of the branching fraction of the B meson decay B{sup 0} {yields} a{sub 1}{sup +}(1260){pi}{sup -}with a{sub 1}{sup +}(1260) {yields} {pi}{sup +}{pi}{sup +}{pi}{sup -}. The data sample corresponds to 218 x 10{sup 6} B{bar B} pairs produced in e{sup +}e{sup -} annihilation through the {Upsilon}(4S) resonance. We find the branching fraction (40.2 {+-} 3.9 {+-} 3.9) x 10{sup -6}, where the first error quoted is statistical and the second is systematic. The fitted values of the a{sub 1}(1260) parameters are m{sub a{sub 1}} = 1.22 {+-} 0.02 GeV/c{sup 2} and {Lambda}{sub a{sub 1}} = 0.423 {+-} 0.050 GeV/c{sup 2}.
Date: July 12, 2005
Creator: Aubert, B.; Barate, R.; Boutigny, D.; Couderc, F.; Karyotakis, Y.; Lees, J. P. et al.
Partner: UNT Libraries Government Documents Department

Measurement of the Partial Branching Fraction for Inclusive Charmless Semileptonic B Decays and Extraction of |Vub|

Description: Charmless semileptonic decays, {bar B} {yields} X{sub u}{ell}{bar {nu}}, are studied in a sample of 232 million B{bar B} decays recorded with the BABAR detector, in events where the decay of the second B meson is fully reconstructed. Inclusive charmless decays are selected in kinematic regions where the dominant background from semileptonic B decays to charm is reduced by requirements on the hadronic mass M{sub X} and the momentum transfer q{sup 2}. The partial branching fraction for {bar B} {yields} X{sub u}{ell}{bar {nu}} decays for M{sub X} < 1.7 GeV/c{sup 2} and q{sup 2} > 8 GeV{sup 2}/c{sup 4} is measured to be {Delta}{Beta}({bar b} {yields} X{sub u}{ell}{bar {nu}}) = (0.87 {+-} 0.09{sub stat} {+-} 0.09{sub sys} {+-} 0.01{sub th}) x 10{sup -3}. The CKM matrix element|V{sub ub}| is determined by using theoretical calculations of phase space acceptances. Theoretical uncertainties in this extrapolation are reduced by using the inclusive b {yields} s{gamma} photon spectrum and moments of the b {yields} c{ell}{bar {nu}} lepton energy and hadronic invariant mass.
Date: July 6, 2005
Creator: Aubert, B.; Barate, R.; Boutigny, D.; Couderc, F.; Karyotakis, Y.; Lees, J. P. et al.
Partner: UNT Libraries Government Documents Department

Measurement of the B0 to pi l nu and B+ to pi0 l nu Branching Fractions and Determination of |Vub| in Upsilon(4S) to BBbar Events Tagged by a Fully Reconstructed B Meson

Description: The authors report preliminary measurements of the charmless exclusive semileptonic branching fractions of the B{sup 0} {yields} {pi}{sup -}{ell}{sup +}{nu} and B{sup +} {yields} {pi}{sup 0}{ell}{sup +}{nu} decays, based on 211 fb{sup -1} of data collected at the {Upsilon}(4S) resonance by the BABAR detector. In events in which the decay of one B meson to a hadronic final state is fully reconstructed, the semileptonic decay of the second B meson is identified by the detection of a charged lepton and a pion. They measure the partial branching fractions for B{sup 0} {yields} {pi}{sup -}{ell}{sup +}{nu} and B{sup +} {yields} {pi}{sup 0}{ell}{sup +}{nu} in three regions of the invariant mass squared of the lepton pair, and they obtain the total branching fractions {Beta}(B{sup 0} {yields} {pi}{sup -}{ell}{sup +}{nu}) = (1.14 {+-} 0.27{sub stat} {+-} 0.17{sub syst}) x 10{sup -4} and {Beta}(B{sup +} {yields} {pi}{sup 0}{ell}{sup +}{nu}) = (0.86 {+-} 0.22{sub stat} {+-} 0.11{sub syst}) x 10{sup -4}. Using isospin symmetry, they measure the combined total branching fraction {Beta}(B{sup 0} {yields} {pi}{sup -}{ell}{sup +}{nu}) = (1.28 {+-} 0.23{sub stat} {+-} 0.16{sub syst}) x 10{sup -4}. Theoretical predictions of the form-factor are used to determine the magnitude of the Cabibbo-Kobayashi-Maskawa matrix element |V{sub ub}| = (3.7 {+-} 0.3{sub stat} {+-} 0.2{sub syst{sub -0.5FF}{sup +0.8}}) x 10{sup -3}, where the last uncertainty is due to the form-factor normalization.
Date: August 26, 2005
Creator: Aubert, B.; Barate, R.; Boutigny, D.; Couderc, F.; Karyotakis, Y.; Lees, J. P. et al.
Partner: UNT Libraries Government Documents Department

Evidence for K ---> K* L+ L- and Measurement of B ---> K L+ L-

Description: The authors present evidence for the flavor-changing neutral current decay B {yields} K*{ell}{sup +}{ell}{sup -} and a measurement of the B {yields} K{ell}{sup +}{ell}{sup -} branching fraction, where {ell}{sup +}{ell}{sup -} is either an e{sup +}e{sup -} or {mu}{sup +}{mu}{sup -} pair. The data sample analyzed comprises 88.5 x 10{sup 6} {Upsilon}(4S) {yields} B{bar B} decays collected with the BABAR detector at the PEP-II e{sup +}e{sup -} storage ring. Averaging over K{sup (*)} isospin and lepton flavor, we obtain {Beta}(B {yields} K*{ell}{sup +}{ell}{sup -}) = (1.40{sub -0.49}{sup +0.57} {+-} 0.21) x 10{sup -6} and {Beta}(B {yields} K{ell}{sup +}{ell}{sup -}) = (0.68{sub -0.15}{sup +0.17} {+-} 0.04) x 10{sup -6}, where the uncertainties are statistical and systematic. The significance for the B {yields} K*{ell}{sup +}{ell}{sup -} signal is 3.0{sigma} and for B {yields} K{ell}{sup +}{ell}{sup -} the signal significance is over 7{sigma}.
Date: August 2, 2005
Creator: Ryd, A.
Partner: UNT Libraries Government Documents Department

Measurements of the Rare Decays B -> Kl+l- and B ->K*l+l-

Description: The authors present measurements of the flavor-changing neutral current decays B {yields} K{ell}{sup +}{ell}{sup -} and B {yields} K*{ell}{sup +}{ell}{sup -}, where {ell}{sup +}{ell}{sup -} is either an e{sup +}e{sup -} or {mu}{sup +}{mu}{sup -} pair. The data sample comprises 229 x 10{sup 6} {Upsilon}(4S) {yields} B{bar B} decays collected with the BABAR detector at the PEP-II e{sup +}e{sup -} storage ring.
Date: July 6, 2005
Creator: Aubert, B.; Barate, R.; Boutigny, D.; Couderc, F.; Karyotakis, Y.; Lees, J. P. et al.
Partner: UNT Libraries Government Documents Department

Measurement of the B0-bar Lifetime and the B0B0-bar Oscillation Frequency Using Partially Reconstructed B0-bar to D*+ l- nu-bar Decays

Description: The authors present a simultaneous measurement of the {bar B}{sup 0} lifetime {tau}{sub B{sup 0}} and B{sup 0}{bar B}{sup 0} oscillation frequency {Delta}m{sub d}. We use a sample of about 50,000 partially reconstructed {bar B}{sup 0} {yields} D*{sup +}{ell}{sup -}{bar {nu}}{sub {ell}} decays identified with the BABAR detector at the PEP-II e{sup +}e{sup -} storage ring at SLAC. The flavor of the other B meson in the event is determined from the charge of another high-momentum lepton.
Date: July 27, 2005
Creator: Aubert, B.; Barate, R.; Boutigny, D.; Couderc, F.; Karyotakis, Y.; Lees, J. P. et al.
Partner: UNT Libraries Government Documents Department

Dalitz-Plot Analysis of the Decays B+/- -> K+/- pi-/+ pi+/-

Description: We report a Dalitz-plot analysis of the charmless hadronic decays of charged B mesons to the state K{sup {+-}} {pi}{sup {-+}}{pi}{sup {+-}}. Using a sample of 226.0 {+-} 2.5 million B{bar B}pairs collected by the BABAR detector, measure the magnitudes and phases of the intermediate resonant and nonresonant amplitudes both charge conjugate decays. We present measurements of the corresponding branching and their charge asymmetries that supersede those of previous BABAR analyses. We find the asymmetries to be consistent with zero.
Date: October 4, 2005
Creator: Aubert, B.; Barate, R.; Boutigny, D.; Couderc, F.; Karyotakis, Y.; Lees, J. P. et al.
Partner: UNT Libraries Government Documents Department

Analysis of B -> omega lv Decays with BaBar (SULI)

Description: As part of the BaBar project at SLAC to study the properties of B mesons, we have carried out a study of the exclusive charmless semileptonic decay mode B {yields} wlv, which can be used to determine the Cabbibo-Kobayashi-Maskawa matrix element V{sub ub}. Using simulated event samples, this study focuses on determining criteria on variables for selection of B {yields} wlv signal and suppression of background from other types of B{bar B} events and continuum processes. In addition, we determine optimal cuts on variables to ensure a good neutrino reconstruction. With these selection cuts, we were able to achieve a signal-to-background ratio of 0.68 and a signal efficiency of the order of 1%. Applying these cuts to a sample of 83 million B{bar B} events recorded by BaBar in e{sup +}e{sup -} collisions at the {Upsilon}(4S) resonance, we obtain a yield of 115 {+-} 19 B {yields} wlv decays.
Date: December 15, 2005
Creator: Chu, Yi-Wen; /MIT; Littlejohn, B.; /Unlisted; Dingfelder, J. & /SLAC
Partner: UNT Libraries Government Documents Department

CP Violation in B Meson Decays: Experimental Results

Description: CP violation is intimately connected with the puzzle of matter-antimatter asymmetry and baryogenesis. In the Standard Model of particle physics, the observed CP violation phenomena are accounted for by the Cabibbo-Kobayashi-Maskawa mechanism involving a phase in the quark mixing matrix. This paper is devoted to a review of the experimental status of CP violation in the decays of B mesons.
Date: August 30, 2005
Creator: Lanceri, Livio & /Trieste U. /INFN, Trieste
Partner: UNT Libraries Government Documents Department

Hadron Physics in BaBar

Description: Some recent results in hadron physics from the BaBar experiment are discussed. In particular, the observation of two new charmed states, the D*{sub sJ}{sup +}(2317) and the D*{sub sJ}{sup +}(2457), is described, and results are presented on the first measurement of the rare decay mode of the B meson, B{sup 0} {pi}{sup 0}{pi}{sup 0}.
Date: August 29, 2005
Creator: Lafferty, G.D. & U., /Manchester
Partner: UNT Libraries Government Documents Department

Electroweak Penguin and Leptonic Decays at BaBar

Description: Recent BABAR results on electroweak penguin and leptonic decays are reviewed. In particular, the measurements of B {yields} K{sup (*)}l{sup +}l{sup -} and the preliminary results on B {yields} X{sub s}l{sup +}l{sup -} are presented. Also summarized are the preliminary limits on B{sup +} {yields} l{sup +}{nu} (l = e,{mu}) and B{sup +} {yields} K{sup +}{nu}{bar {nu}}.
Date: August 26, 2005
Creator: Bucci, F. & /Pisa U. /INFN, Pisa
Partner: UNT Libraries Government Documents Department