We measure the rate of D0-D0bar mixing with the observable yCP=(tauKpi/tauKK)-1, where tauKK and tauKpi are respectively the mean lifetimes of CP-even D0->K+K- and CP-mixed D0->K-pi+ decays, using a data sample of 384/fb collected by the Babar detector at the SLAC PEP-II asymmetric-energy B Factory. From a sample of D0 and D0bar decays where the inital flavor of the decaying meson is not determined, we obtain yCP = [1.12 +/- 0.26 (stat) +/- 0.22 (sys)]%, which excludes the no-mixing hypothesis at 3.3 sigma, including both statistical and systematic uncertainties. This result is in good agreement with a previous Babar measurement of yCP obtained from a sample of D*+->D0pi+ events, where the D0 decays to K-pi+, K+K-, and pi+pi-, which is disjoint with the untagged D0 events used here. Combining the two results taking into account statistical and systematic uncertainties, where the systematic uncertainties are assumed to be 100% correlated, we find yCP = [1.16 +/- 0.22 (stat) +/- 0.18 (sys)]%, which excludes the no-mixing hypothesis at 4.1 sigma.
A review of recent experimental measurements of the lifetime and mixing parameters of neutral D and B hadrons is presented. In particular, focus is given to measurements of D mixing and the Lambda_B lifetime.
Recent results on Bs mixing, lifetime difference and rare decays obtained by the CDF and DO collaborations using the data samples collected at the Tevatron Collider in the period 2002 - 2005 are presented.
The measurements of the \Bs mixing parameter which describes the difference in width (the inverse of the lifetime) between the \Bs heavy and light states are described. These measurements include direct measurement of $ΔΓ_s$ and $Γ_s$ by resolving CP eigenstates by angular analysis and measurements in which the proportion of CP even and odd is known.
We present the latest $B$ hadron lifetimes, $B^0_s$ mixing, and $D^0$ mixing measurements using up to 3.0 fb$^{-1}$ of data collected by CDF and D0 experiments at Fermilab. The $B^0_s$ lifetime is measured from both $J/ψϕ$ (CP admixture) and flavor specific channels, and the $B_c$ lifetime is obtained from semileptonic channels. Following the $B^0_s$ oscillation frequency measurement at CDF in 2006, the D0 collaboration now observes $B^0_s$ oscillation at a significance of about 3$σ$. Since the first $D^0$ mixing evidence established at $B$ factories in 2007, CDF has observed $D^0$ mixing at a…
The Tevatron collider at Fermilab provides a very rich environment for the study of b-hadrons. Both the D0 and CDF experiments have collected a sample of about 1 fb^{-1}. We report results on three topics: b-hadron lifetimes, polarization amplitudes and the decay width difference in Bs to Jpsi Phi, and Bs mixing.
Recent BaBar measurements on lifetime and mixing of B mesons are reported. Various techniques are used, ranging from the full reconstruction of hadronic B decays, to partial reconstruction techniques, and to a totally inclusive approach with dilepton events. The results presented are based on a data sample collected by BaBar during the 1999-2000 data taking, and should be considered as preliminary.
We present recent results on b-hadron lifetimes and mixing obtained from the analysis of the data collected at the Tevatron Collider by the CDF and D0 Collaborations in the period 2002 - 2004. Many lifetime measurements have been updated since the Summer 2004 conferences, sometimes improving significantly the accuracy. Likewise the measurement of the $B_d$ oscillation frequency has been updated. New limits on the $B_s$ oscillation frequency have been determined using for the first time Run II data.
Time-dependent B0-antiB0 flavor oscillations and B0 and B+ lifetimes are studied in a sample of fully reconstructed B mesons collected with the BaBar detector, running at the PEP-II asymmetric e+e- B Factory with center-of-mass energies near the Upsilon(4S) resonance. This is the first time that time-dependent mixing and lifetime measurements have been performed at Upsilon(4S) energies.
We present the CDF results using 1.0 fb^{-1} of data on the mixing frequency measurement in the B_s system and the lifetime measurements of several B hadrons. We obtain Δm_s=17.77 +- 0.1 +- 0.07 ps^{-1} and cτ(Λ_b)=473.8 +- 23.1 +- 3.5 μm. The later one is more than 3 sigma above the world average, but in reasonable agreement with HQE calculations.
The Tevatron, with p p-bar collisions at sqrt(s)=1.96TeV can produce all flavors of B hadrons and allows for unprecedented studies in the B physics sector. The CDF and D0 collaborations have more than 5 fb-1 of data recorded. I present here a selection of results on the masses, lifetimes and mixings of B hadrons using between 1.0 and 2.8fb-1 of data.
A review of the latest results on charm lifetimes and D-mixing is presented. The e+e- collider experiments are now able to measure charm lifetimes quite precisely, however comparisons with the latest results from fixed-target experiments show that possible systematic effects could be evident. The new D-mixing results from the B-factories have changed the picture that is emerging. Although the new world averaged value of y_CP is now consistent with zero, there is still a very interesting and favoured scenario if the strong phase difference between the Doubly-Cabibbo-suppressed and the Cabibbo-f…
The lifetimes of charmed mesons have been measured using 11.1fb$^{-1} of data collected with the Belle detector at KEKB. Each candidate is fully reconstructed to identify the flavor of the charmed meson. The lifetimes are measured to be $τ(D^0)=(414.5\pm1.7)$ fs, $τ(D^+)=(1029\pm12)$ fs and $τ(D_s^+)=(488.4^{+7.8}_{-7.7})$ fs, where the error is statistical only. The mixing parameter $y_{CP}$ is also measured to be $y_{CP}=(1.16^{+1.67}_{-1.65}(stat.))%$ through the lifetime difference of $D^0$ mesons decaying into CP-mixed states and CP eigenstates.
The Tevatron experiments, CDF and D0, have produced a wealth of new B-physics results since the start of Run II in 2001. We've observed new B-hadrons, seen new effects, and increased many-fold the precision with which we know the properties of b-quark systems. In these proceedings, we will discuss two of the most fruitful areas in the Tevatron B-physics program: lifetimes and mixing. We'll examine the experimental issues driving these analyses, present a summary of the latest results, and discuss prospects for the future.
We review latest experimental results on the Bs mixing and lifetime difference measurements at CDF. We report on the latest beta_s and dGamma_s results from Bs->J/psi phi. We also discuss flavor specific dGamma_s measurements, including information from hadronic channels, Bs->DsDs and Bs->KK. We describe the new flavor tagging methodology and its calibration using the Bs oscillations.
Preliminary limits on the D^0 mixing parameter y = ΔΓ/ 2 Γare obtained using about 57.8 fb^-1 of data collected by BaBar in 2000 and 2001:y = (1.4 \pm 1.0 (stat.) +0.6 -0.7 (syst.))%. y is extracted, provided that CP is conserved, by measuring separately the D^0 lifetime for the Cabibbo-suppressed decay modes K- K+, π- π+ and the Cabibbo-favoured mode K- π+. Backgrounds are suppressed by D*-tag and particle identification requirements.
We present a measurement of $D^0$-$\D0bar$ mixing parameters using the ratios of lifetimes extracted from samples of $D^0$ mesons decaying to $K^-π^+$, $K^-K^+$, and $π^-π^+$. Using 91 ${\rm fb}^{-1}$ of data collected by the BaBar detector at the PEP-II asymmetric-energy $B$ Factory, we obtain a value $Y = (0.8 \pm 0.4 ({\rm stat.}) {}^{+0.5}_{-0.4} ({\rm syst.}))$%, which, in the limit of CP conservation, corresponds to the mixing parameter $y = ΔΓ/2Γ$. Using the difference in lifetimes of $D^0$ and $\D0bar$ mesons, we obtain the CP-violation parameter $ΔY = (-0.8 \pm 0.6 ({\rm stat.}) \pm 0…
We report the observation of CP violation in the $B^0$ meson system. Using a novel technique for time-dependent measurements, we measure a non-zero value for the CP-violating amplitude $\sin 2β$ at the 4.1 $σ$ level. We also report on precision measurements of the $B^+$ and $B^0$ lifetimes and the $B^0\bar{B}^0$ mixing frequency $Δm_d$ obtained with the same technique and on a first measurement of the time-dependent CP-violating amplitude in $B^0\to π^+π^-$ decays.
The Fermilab Tevatron offers unique opportunities to perform measurements of the heavier B hadrons that are not accessible at the Upsilon(4S) resonance. In this summary, we describe some recent heavy flavor results from the DO and CDF collaborations and discuss prospects for future measurements.
We report new preliminary B Physics results obtained with 300,000 hadronic Z0 decays collected by the SLD experiment at the SLC between 1993 and 1997. Three analyses are presented: a measurement of B+ and B0 lifetimes, a study of the time dependence of Bs - Bs-bar mixing, and a search for decays of the type b --> sg. All analyses benefit from the small and stable interaction point and the excellent resolution and efficiency provided by the pixel-based CCD Vertex Detector. The b --> sg analysis also exploits the particle identification capabilities of the Cherenkov Ring Imaging Detector.
The BaBar collaboration has analysed 60M BB_ pairs collected at the Upsilon (4S) resonance at the PEP II asymetric collider at SLAC. Using this data sample we have measured the CP violation parameters sin (2beta)=0.75+/- 0.09 (STAT) +/-0.04 (SYST) and lambda =0.92+/- 0.06 (STAT) +/- 0.02 (SYST) from B0 to cc_+K*0 + c.c. decays. From charmless 2-body B decays we measure A_Kpi =-0.05 +/- 0.06 +/- 0.01(-0.14,+0.05), S_pipi = -0.01 +/- 0.37 +/- 0.07(-0.66,+0.62), C_pipi =-0.02 +/- 0.29 +/- 0.07(-0.54,+0.48). A number of B lifetime and mixing parameters, extracted from subsamples of this data set, …
The BABAR detector, which operates at the SLAC PEPII asymmetric e+e- collider at energies near the Y(4S) resonance has collected about 23M B-anti-B pairs in year 2000. Based on this data sample, we present the first study of sin(2b), with samples of B^0 --> J/psi K0S, B^0 --> psi(2S) K0S and B^0 --> J/psi K0L decays. The measured value is 0.34+-0.20+-0.05. In addition, we present preliminary measurements of charged and neutral B meson lifetimes and B^0-anti-B^0 oscillation frequency.
With an integrated luminosity of 7.7 fb-1 collected on resonance by BABAR at the PEP-II asymmetric B Factory, we measure the difference in mass between the neutral B eigenstates, Delta(m_d), to be (0.507+/-0.015+/-0.022)x 10^{12} hbar s^{-1} with dileptons events and present preliminary results for the B^0 lifetime, tau(B^0) = 1.55+/-0.05+/-0.07 ps and tau(B^0) = 1.62+/-0.02+/-0.09 ps obtained from partial reconstruction of the two B^0 decay processes respectively B^0-->D^{*-}pi^+ and B^0-->D^{*-} l^+ nu_l.
This paper emphasizes four topics that represent some of the year's highlights in heavy quark physics. First of all, a review is given of charm lifetime measurements and how they lead to better understanding of the mechanisms of charm decay. Secondly, the CLEO collaboration's new search for charm mixing is reported, which significantly extends the search for new physics in that sector. Thirdly, important updates in Bs mixing are summarized, which result in a new limit on the mass difference, and which further constrain the unitarity triangle. Finally, the first efforts to measure CP violation …
The BaBar detector at the PEP-II asymmetric B Factory at SLAC collected a sample of 23M B-anti-B pairs in the years 1999 and 2000. Using this data sample, we measure the amplitude of the time-dependent CP-violating asymmetry in neutral B decays to the CP eigenstates B0 --> J/psi K0S, B0 --> psi(2S) K0S and B0 --> J/psi K0L. We find a value of sin2beta = 0.34 +/- 0.20 (stat) +/- 0.05 (syst). We also present preliminary measurements of the B^0-anti-B^0 oscillation frequency and of the lifetimes of charged and neutral B mesons.
Recent results on the $B$ CP-violation parameter $\sin2ϕ_1$, the $B^0_d$-$\overline{B}^0_d$ mixing parameter $Δm_d$ and $B$-meson lifetimes are reported. The results are based on 10.5 $fb^{-1}$ of data collected with the Belle detector at KEKB. Using both semileptonic and hadronic decay modes the neutral and charged $B$-meson lifetimes are measured to be $\taubz=1.548\pm0.035 (\mathrm{stat.})$~ps and $\taubm=1.656\pm0.038 (\mathrm{stat.})$~ps. The oscillation frequency $Δm_d$ for $B^0_d$-$\overline{B}^0_d$ mixing is measured to be $0.522\pm0.026 (\mathrm{stat.})$~ps$^{-1}$ using semileptonic m…
We present a measurement of $D^0$-$\bar{D^0}$ mixing parameters using the ratios of lifetimes extracted from a sample of $D^0$ mesons produced through the process $D^{*+}\to\D^0π^+$, that decay to $K^{+}π^{-}$, K^{-}K^{+}$, or $π^-π^+$. The Cabibbo-suppressed modes $K^{-}K^{+}$ and $π^-π^+$ are compared to the Cabibbo-favored mode $K^{+}π^{-}$ to obtain a measurement of $y_{CP}$, which in the limit of CP conservation corresponds to the mixing parameter $y$. The analysis is based on a data sample of 384 $fb^{-1}$ collected by the $BaBar$ detector at the PEP-II asymmetric-energy $e^+e^-$ collide…
We measure the B0 lifetime tau_B0 and the B-Bbar oscillation frequency Deltam_d with a sample of approximately 14,000 exclusively reconstructed B0 -> D*- l+ nu_l signal events, selected from 23 million B-Bbar pairs recorded at the Upsilon(4S) resonance with the BABAR detector at the Stanford Linear Accelerator Center. The b-quark flavor of the other B at the time of decay and its decay position are determined inclusively. The lifetime and oscillation frequency are measured simultaneously with an unbinned maximum-likelihood fit that uses, for each event, the measured difference in B decay times…
Current status of charm mixing search, lifetime difference measurement and rare decay search are reported. The best upper limit at 95% CL for mixing is reported from the CLEO collaboration. E791 has reported lifetime difference measurement and results of rare decay searches. Rare decay searches of the FOCUS collaboration are in progress and their sensitivities to branching ratios are at the level of a few x 10^{-6}.
Recent results of a high-statistics study of tau lepton properties and decays at B factories are reviewed. We discuss measurements of tau lifetime, branching fractions, and spectral functions for several hadronic tau decay modes with $K^0_S$. Results of a search for lepton flavor violating tau decays as well as CP symmetry violation are briefly discussed.
The latest results in B physics from the CDF and D0 experiments at the Tevatron are presented, including inclusive b lifetime measurement and exclusive lifetime measurement of the B_s. Promising samples collected by CDF with its Secondary Vertex Trigger are shown as well.
The D^0 mixing parameter y = Delta Gamma/2 Gamma was determined by measuring the D^0 lifetime separately for the K^-pi^+ decay mode and the K^-K^+ decay mode with 12.4 fb^{-1} of data collected by the BABAR experiment in 2001. Backgrounds were suppressed with the D^* --> D^0pi^+ decay and particle identification. The following preliminary result was obtained: y = (-1.0 +/- 2.2 (stat) +/- 1.7 (syst))%.
Using a data sample of 62 million \FourS\to B\Bbar decays collected between 1999 and 2001 by the BaBar detector at the PEP2 asymmetric-energy B Factory at SLAC we study events in which one neutral B meson is fully reconstructed in a final state containing a charmonium meson and the flavour of the other neutral B meson is determined from its decay products. The amplitude of the CP-violating asymmetry, which in the Standard Model is proportional to sin(2 beta), is derived from the decay time distributions. We measure sin(2 beta) = 0.75 \pm 0.09 (stat) \pm 0.04 (syst) and |λ| = 0.92 \pm 0.06 (sta…
We discuss neutral B_{s,d} meson mixing and b-hadron lifetimes from the perspective of recent lattice calculations. In particular, we consider matrix elements which can be combined with measured ΔM_{s,d} to constrain |V_{td}|, the lifetime ratios τ(Λ_b)/τ(B_d) and τ(B^-)/τ(B_d) and the lifetime difference, ΔΓ_s/Γ_s, in the neutral B_s meson system.
Using data samples in excess of 1 fb^-1 collected by the CDF II detector we present several world's best measurements of B hadron lifetimes. They include B_s meson lifetime in a flavor-specific decay mode, combining fully and partially reconstructed hadronic decays, B_c^+ meson lifetimes in semileptonic B_c^+ -> J/psi l+ X, l+=mu+,e+ decays and Lambda_b baryon lifetime in Lambda_c^+ pi- fully-reconstructed decays. In addition, we introduce a Monte Carlo independent technique for measuring B hadron lifetimes in data samples biased by displaced vertex triggers.
We measure the B0 lifetime τ_{B0} and the B0-B0bar oscillation frequency Δm_d with a sample of approximately 14,000 exclusively reconstructed B0 --> D*- l+ nu signal events, selected from 23 million BBbar pairs recorded at the Υ(4S) resonance with the BABAR detector at the Stanford Linear Accelerator Center. The decay position of the other B is determined with the remaining tracks in the event, and its b-quark flavor at the time of decay is determined with a tagging algorithm that exploits the correlation between the flavor of the b-quark and the charges of its decay products. The lifetime and…
Measurements of the effective lifetimes of $B_s$-meson decays, which only require untagged rate analyses, allow us to probe the width difference $ΔΓ_s$ and the CP-violating phase $ϕ_s$ of $B^0_s$-$\bar B^0_s$ mixing. We point out that the dependence of the effective lifetime on non-linear terms in $ΔΓ_s$ allows for a determination of $ϕ_s$ and $ΔΓ_s$ given a pair of $B_s$ decays into CP-even and CP-odd final states. Using recent lifetime measurements of $B^0_s\to K^+K^-$ and $B^0_s\to J/ψf_0(980)$ decays, we illustrate this method and show how it complements the constraints in the $ϕ_s$-$ΔΓ_s$…
From a sample of about 10^9 Phi mesons produced at DAFNE, we have selected KL mesons tagged by observing KS->pi+pi- decays. We present results on the major KL branching ratios, including those of the semileptonic decays needed for the determination of Vus. These branching ratio measurements are fully inclusive with respect to final-state radiation. The KL lifetime has also been measured.
Precision lifetime measurements of $b$-flavoured hadrons are an important test of the validity of the theoretical tool used to determine $b$-hadrons observables, the Heavy Quark Expansion. Recent measurements of the $B^+$, $Λ^0_b$, $Ξ^-_b$, $Ξ^0_b$ and $Ω^-_b$ hadrons lifetimes are reported. Moreover, several $B^0$ and $B^0_s$ effective lifetime measurements are discussed, as well as a measurement of the decay width difference in the $B^0$ system, $ΔΓ_d$. All the measurements have been performed using $pp$ collision data collected with the LHCb detector.
We have measured the Lambda_b lifetime using the exclusive decay Lambda_b to J/psi Lambda, based on 1.2 fb-1 of data collected with the D0 detector during 2002-2006. From 171 reconstructed Lambda_b decays, where the J/psi and Lambda are identified via the decays J/psi to mu+ mu- and Lambda to p pi, we measured the Lambda_b lifetime to be tau(Lambda_b) = 1.218(+0.130,-0.115)(stat) +/- 0.042(syst)ps. We also measured the B0 lifetime in the decay B0 to J/psi(mu+ mu-)K0_S(pi+ pi-) to be tau(B0) = 1.501(+0.078,-0.074)(stat) +/ -0.050(syst)ps, yielding a lifetime ratio of tau(Lambda_b)/tau(B0) = 0.8…
The neutral B meson lifetime has been measured with the data collected by the BABAR detector at the PEP-II storage ring during the year 2000 for a total integrated luminosity of 20.3 fb-1. The B0 --> D*- pi+ decays have been selected with a partial reconstruction method in which only the fast pion from the B0 decay and the slow pion from D*- --> D0 bar pi- are reconstructed. The B0 lifetime has been measured to be 1.510 +/- 0.040 +/- 0.038 ps with a sample of 6971 +/- 241 reconstructed signal events.
The lifetime of the Bs0 meson is measured using the semileptonic decay Bs0 --> Ds- l+ nu X. The data sample consists of about 110 pb^-1 of pp= collisions at sqrt{s} = 1.8 TeV collected by the CDF detector at Fermilab. Four different Ds- decay modes are reconstructed resulting in approximately 600 Ds-l+ signal events. The Bs0 meson lifetime is determined to be tau(Bs0) = (1.36 +- 0.09 +0.06-0.05) ps, where the first and second uncertainties are statistical and systematic, respectively. The Bs0 meson decay length distribution is examined for a lifetime difference Delta_Gamma/Gamma between the tw…
We present measurements of the Lambda^0_b lifetime in the exclusive decay channel Lambda^0_{b}->J/psi Lambda^0, with J/psi to mu+ mu- and Lambda^0 to p pi-, the B^0 lifetime in the decay B^0 -> J/psi K^0_S with J/psi to mu+ mu- and K^0_S to pi+ pi-, and the ratio of these lifetimes. The analysis is based on approximately 250 pb^{-1} of data recorded with the D0 detector in pp(bar) collisions at sqrt{s}=1.96 TeV. The Lambda^0_b lifetime is determined to be tau(Lambda^0_b) = 1.22 +0.22/-0.18 (stat) +/- 0.04 (syst) ps, the B^0 lifetime tau(B^0) = 1.40 +0.11/-0.10 (stat) +/- 0.03 (syst) ps, and th…
We report a measurement of the $B^0_{s}$ lifetime in the semileptonic decay channel $B^0_{s}\to D^-_s μ^{+}νX$ (and its charge conjugate), using approximately 0.4 fb$^{-1}$ of data collected with the D0 detector during 2002 -- 2004. We have reconstructed 5176 $D^-_s μ^{+}$ signal events, where the $D_s^-$ is identified via the decay $D_s^-\to ϕπ^-$, followed by $ϕ\to K^+ K^-$. Using these events, we have measured the $B^0_s$ lifetime to be $τ(B^0_{s}) = 1.398 \pm 0.044$ $({stat}) ^{+0.028}_{-0.025}$ $({syst}) {ps}$. This is the most precise measurement of the $B_s^0$ lifetime to date.
The lifetime of the $B_c^{-}$ meson is measured using 272 exclusive $B_{c}^{-} \to J/ψ(\to μ^+μ^-) π^-$ decays reconstructed in data from proton-antiproton collisions corresponding to an integrated luminosity of 6.7 fb$^{-1}$ recorded by the CDF II detector at the Fermilab Tevatron. The lifetime of the $B_c^{-}$ meson is measured to be $τ$($B_c^{-}$) = 0.452 $\pm$ 0.048(stat) $\pm$ 0.027(syst) ps. This is the first measurement of the $B_c^{-}$ meson lifetime in a fully-reconstructed hadronic channel, and it agrees with previous results and has comparable precision.
Using events in which one of two neutral B mesons from the decay of an Y(4S) resonance is fully reconstructed, we set limits on the lifetime difference between the two neutral-B mass eigenstates and on CP, T, and CPT violation in B0-B0bar mixing. Both CP and non-CP eigenstates were obtained from the 88 million Y(4S)->B0B0bar decays collected between 1999 and 2002 with the BABAR detector at the PEP-II asymmetric-energy B-Factory at SLAC. We determine six independent parameters governing mixing (dm, dGamma/Gamma), CPT/CP violation (Re(z), Im(z)), and CP/T violation (Imλ(CP), |q/p|), where λ(CP) …
The data collected during the 2006 total solar eclipse are analyzed in the search for signals produced by a hypothetical radiative decay of massive neutrinos. In the absence of the expected light pattern, we set lower limits for the massive neutrino components proper lifetime. The reached sensitivity indicates thet these are the best limits obtainable with this method.
We report a measurement of the Lambda_b lifetime using a sample corresponding to 1.3 fb$^{-1}$ of data collected by the D0 experiment in 2002--2006 during Run II of the Fermilab Tevatron collider. The Lambda_b baryon is reconstructed via the decay Lambda_b -> mu nu Lambda_c X. Using $4437 \pm 329$ signal candidates, we measure the Lambda_b lifetime to be $τ(Lambda_b)$ = 1.290^{+0.119}_{-0.110}(stat) ^{+0.087}_{-0.091} (syst) ps, which is among the most precise measurements in semileptonic Lambda_b decays. This result is in good agreement with the world average value.
Using approximately 1.3 fb-1 of data collected by the D0 detector between 2002 and 2006, we measure the lifetime of the B_c meson in the B_c -> J/psi mu nu X final state. A simultaneous unbinned likelihood fit to the J/ψ+mu invariant mass and lifetime distributions yields a signal of 881 +/- 80 (stat) candidates and a lifetime measurement of τ(B_c) = 0.448 +0.038 -0.036 (stat) +/- 0.032 (syst) ps.
We present a precise measurement of the standard model CP-violation parameter sin(2phi1), the direct CP violation parameter |lambda|, the lifetimes of charged and neutral B mesons and their ratio, and the B0-B0bar mixing parameter Delta m_d based on a sample of 152 x 10^6 BB-bar pairs collected at the Y(4S) resonance with the Belle detector at the KEKB asymmetric-energy e+e- collider. One of two B mesons is fully reconstructed in a CP-eigenstate or a flavor-eigenstate decay channel. The flavor of the accompanying B meson is identified from its decay products. From the asymmetry in the distribu…
We measure the Lambda_b^0 lifetime in the fully reconstructed decay Lambda_b^0 -> J/psi Lambda^0 using 10.4 fb^-1 of ppbar collisions collected with the D0 detector at sqrt(s)=1.96 TeV. The lifetime of the topologically similar decay channel B^0 -> J/psi K^0_S is also measured. We obtain tau(Lambda_b^0) = 1.303 +- 0.075 (stat.) +- 0.035 (syst.) ps and tau(B^0) = 1.508 +- 0.025 (stat.) +- 0.043 (syst.) ps. Using these measurements, we determine the lifetime ratio of tau(Lambda_b^0)/tau(B^0) = 0.864 +- 0.052 (stat.) +- 0.033 (syst.).
The B0 lifetime has been measured with a sample of 23 million BBbar pairs collected by the BaBar detector at the PEP-II e+e- storage ring during 1999 and 2000. Events from the semileptonic decay B0 --> D*- l+ nu have been selected with a partial reconstruction method in which only the charged lepton and the slow pion from the D*- --> D0bar pi- decay are reconstructed. The result is tau_B0 = 1.529+/-0.012 (stat) +/- 0.029 (syst) ps.
We present a measurement of the Bs lifetime in fully and partially reconstructed Bs -> Ds(phi pi)X decays in 1.3 fb-1 of pbar-p collisions at sqrt(s) = 1.96 TeV collected by the CDF II detector at the Fermilab Tevatron. We measure tau(Bs) = 1.518 +/- 0.041 (stat.) +/- 0.027 (syst.) ps. The ratio of this result and the world average B0 lifetime yields tau(Bs)/tau(B0) = 0.99 +/-0.03, which is in agreement with recent theoretical predictions.
The lifetimes of the B- and B0-bar mesons are measured using the partially reconstructed semileptonic decays B-bar -> D l- nu-bar X, where D is either a D0 or D*+ meson. The data were collected by the CDF detector at the Fermilab Tevatron collider during 1992-95 and correspond to about 110 pb-1 of p-bar p collisions at sqrt(s)=1.8 TeV. We measure decay lengths and extract the lifetimes to be tau(B-) = 1.637 +/- 0.058 +0.045 -0.043 ps, tau(B0) = 1.474 +/- 0.039 +0.052 -0.051 ps, and the ratio of the lifetimes to be tau(B-)/tau(B0) = 1.110 +/- 0.056 +0.033 -0.030, where the first uncertainties a…
Data collected with the BABAR detector at the PEP-II asymmetric B Factory at SLAC are used to study the lifetimes of the B^0 and B^+ mesons. The data sample consists of 7.4 fb-1 collected near the Y(4S) resonance. B^0 and B^+ mesons are fully reconstructed in several exclusive hadronic decay modes to charm and charmonium final states. The B lifetimes are determined from the flight length difference between the two B mesons which are pair-produced in the Y(4S) decay. The preliminary measurements of the lifetimes are tau_B0 = 1.506+/-0.052(stat)+/-0.029(syst) ps, tau_B+ = 1.602+/-0.049(stat)+/-0…
Data collected with the BABAR detector at the PEP-II asymmetric B Factory at SLAC are used to study the lifetime of the B0 and B+ mesons. The data sample consists of 7.4 fb-1 collected near the Y(4S) resonance. B0 and B+ mesons are fully reconstructed in several exclusive hadronic decay modes to charm and charmonium final states. The B lifetime are determined from the flight length difference between the two B mesons. The preliminary measurements of the lifetimes are tau_{B0} = 1.506 +/- 0.052 (stat) +/- 0.029 (syst) ps tau_{B+} = 1.602 +/- 0.049 (stat) +/- 0.035 (syst) ps and of their ratio i…
The lifetimes of B+ and B0 mesons are measured using a sample of 150,000 hadronic Z0 decays collected by the SLD experiment at the SLC between 1993 and 1995. The analysis identifies the semileptonic decays of B mesons and reconstructs the B meson decay length and charge by vertexing the lepton with a partially reconstructed D meson. This new method results in a sample of 634 (584) charged (neutral) decays with high charge purity. The ratio of B+ : B0 decays in the charged (neutral) sample is 3:1 (1:3). A maximum likelihood fit yields t(B+) = 1.61 +0.13 -0.12(stat) +/- 0.07(syst) ps, t(B0) = 1.…
We review the status of bottom quark physics at the CDF experiment. The measurements reported are based on about 110 pb-1 of data collected at the Fermilab Tevatron pp= Collider operating at sqrt{s} = 1.8 TeV. In particular, we review results on B hadron lifetimes, measurements of the time dependence of B0 B0= oscillations, and a search for CP violation in B0 --> J/Psi K0s decays. Prospects for future B physics at CDF in the next run of the Tevatron Collider starting in the year 2000 are also given.
