The Experts below are selected from a list of 252 Experts worldwide ranked by ideXlab platform
Chee-yee Chong - One of the best experts on this subject based on the ideXlab platform.
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Comparison of track fusion rules and track association metrics
2012 15th International Conference on Information Fusion, 2012Co-Authors: Shozo Mori, Kuo-chu Chang, Chee-yee ChongAbstract:This paper presents numerical performance evaluation of various algorithms that have been developed for track-to-track fusion and association problems, through a long history of the distributed multiple target tracking algorithm development. We will use a general linear-Gaussian Standard model both for the target state and the sensor observation models. Doing so, we can analytically evaluate any linear track fusion rule that produces a global target state estimate by fusing local target state estimates obtained by local sensor processing systems. In order to clearly compare performance of various track fusion rules, we will only utilize simple two-station (two-sensor) track association and fusion problems. Two typical situations, supplementary and complementary sensor scenarios, will be considered. Repeated track fusion with and without feedback will be examined in addition to simple one-time track fusion. For track-to-track association performance, we will compare the effects of using various track association metrics, proposed so far, in a simple one-time track association problem, through Monte Carlo methods.
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FUSION - Comparison of track fusion rules and track association metrics
2012Co-Authors: Shozo Mori, Kuo-chu Chang, Chee-yee ChongAbstract:This paper presents numerical performance evaluation of various algorithms that have been developed for track-to-track fusion and association problems, through a long history of the distributed multiple target tracking algorithm development. We will use a general linear-Gaussian Standard model both for the target state and the sensor observation models. Doing so, we can analytically evaluate any linear track fusion rule that produces a global target state estimate by fusing local target state estimates obtained by local sensor processing systems. In order to clearly compare performance of various track fusion rules, we will only utilize simple two-station (two-sensor) track association and fusion problems. Two typical situations, supplementary and complementary sensor scenarios, will be considered. Repeated track fusion with and without feedback will be examined in addition to simple one-time track fusion. For track-to-track association performance, we will compare the effects of using various track association metrics, proposed so far, in a simple one-time track association problem, through Monte Carlo methods.
T Aaltonen - One of the best experts on this subject based on the ideXlab platform.
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Observation of D0-D ̄ 0 mixing using the CDF II detector
Physical Review Letters, 2013Co-Authors: T Aaltonen, B. Casal, Javier Cuevas, G. Gomez, E. Palencia, Alberto Ruiz Jimeno, Luca Scodellaro, R. Vilar, J. VizánAbstract:We measure the time dependence of the ratio of decay rates for D0→K+π− to the Cabibbo-favored decay D0→K−π+. The charge conjugate decays are included. A signal of 3.3×104 D*+→π+D0, D0→K+π−decays is obtained with D0 proper decay times between 0.75 and 10 mean D0 lifetimes. The data were recorded with the CDF II detector at the Fermilab Tevatron and correspond to an integrated luminosity of 9.6 fb−1 for pp¯ collisions ats√=1.96 TeV. Assuming CP conservation, we search for D0-D¯¯¯0 mixing and measure the mixing parameters to be RD=(3.51±0.35)×10−3, y′=(4.3±4.3)×10−3, and x'2=(0.08±0.18)×10−3. We report Bayesian probability intervals in the x'2-y′ plane and find that the significance of excluding the no-mixing hypothesis is equivalent to 6.1 Gaussian Standard deviations, providing the second observation of D0-D¯¯¯0 mixing from a single experiment.
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Measurement of the difference in CP-violating asymmetries in D0→K +K - and D0→π +π - decays at CDF
Physical Review Letters, 2012Co-Authors: T Aaltonen, S Amerio, A Anastassov, J Antos, B. Alvarez Gonzalez, Dante Amidei, Alberto Annovi, G. Apollinari, J. A. Appel, Tetsuo ArisawaAbstract:We report a measurement of the difference (D/Acp) between time-integrated-violating asymmetries in D{sup 0} K{sup +}K{sup -} and D{sup 0} {pi}{sup +}{pi}{sup -} decays reconstructed in the full data set of proton-antiproton collisions collected by the Collider Detector at Fermilab, corresponding to 9.7 fb{sup -1} of integrated luminosity. The strong decay D*{sup +} D{sup 0}{pi}{sup +} is used to identify the charm meson at production as D{sup 0} or ['D]{sup 0}. We measure D/Acp = (-0.62 0.21 /stat 0.10 /syst)%, which differs from zero by 2.7 Gaussian Standard deviations. This result supports similar evidence for violation in charm-quark obtained in proton-proton collisions.
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Measurement of theCP-violating phaseβsJ/ψϕinBs0→J/ψϕdecays with the CDF II detector
Physical Review D, 2012Co-Authors: T Aaltonen, S Amerio, D Amidei, A Anastassov, A Annovi, J Antos, B. Alvarez Gonzalez, G. Apollinari, J. A. Appel, T. ArisawaAbstract:We present a measurement of the CP-violating parameter βsJ/ψ using approximately 6500 Bs0→J/ψ decays reconstructed with the CDF II detector in a sample of pp collisions at √s=1.96TeV corresponding to 5.2fb -1 integrated luminosity produced by the Tevatron collider at Fermilab. We find the CP-violating phase to be within the range βsJ/ψ [0.02,0.52] [1.08,1.55] at 68% confidence level where the coverage property of the quoted interval is guaranteed using a frequentist statistical analysis. This result is in agreement with the Standard model expectation at the level of about one Gaussian Standard deviation. We consider the inclusion of a potential S-wave contribution to the Bs0→J/ψK +K - final state which is found to be negligible over the mass interval 1.009
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Observation of the Ωb- baryon and measurement of the properties of the Ξb- and Ωb- baryons
Physical Review D, 2009Co-Authors: T Aaltonen, J Adelman, T Akimoto, A Anastassov, J Antos, B. Alvarez Gonzalez, Silvia Amerio, Dante Amidei, Alberto Annovi, G. ApollinariAbstract:We report the observation of the bottom, doubly-strange baryon Ω ― b through the decay chain Ω ― b → J/ψΩ ― , where J/ψ → μ + μ ― , Ω ― → ΛK ― , and Λ → pπ ― , using 4.2 fb ―1 of data from pp collisions at s = 1.96 TeV, and recorded with the Collider Detector at Fermilab. A signal is observed whose probability of arising from a background fluctuation is 4.0 × 10 ―8 , or 5.5 Gaussian Standard deviations. The Ω ― b mass is measured to be 6054.4 ± 6.8(stat) ± 0.9(syst) MeV/c 2 . The lifetime of the Ω ― b baryon is measured to be 1.13 +0.53 ―0.40 (stat) ± 0.02(syst) ps. In addition, for the ― b baryon we measure a mass of 5790.9 ± 2.6(stat) ± 0.8(syst) MeV/c 2 and a lifetime of 1.56 ±0.27 ―0.25 (stat) ± 0.02(syst) ps. Under the assumption that the ― b and Ω ― b are produced with similar kinematic distributions to the Λ 0 b baryon, we find σ( ― b )B( ― b →J/ψ ― ) σ(Λ 0 b )B(Λ 0 b )→J/ψΛ) = 0.167 ±0.037 ―0.025 (stat) ± 0.012(syst) and σ(Ω ― b )B(Ω ― b →J/ψΩ ― ) σ(Λ 0 b )B(Λ 0 b →J/ψΛ) = 0.045 ±0.017 ―0.012 (stat) ± 0.004(syst) for baryons produced with transverse momentum in the range of 6―20 GeV/c.
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First Flavor-Tagged Determination of Bounds on Mixing-InducedCPViolation inBs0→J/ψϕDecays
Physical Review Letters, 2008Co-Authors: T Aaltonen, J Adelman, T Akimoto, S Amerio, D Amidei, A Anastassov, A Annovi, M. G. Albrow, B. Alvarez Gonzalez, J AntosAbstract:This Letter describes the first determination of bounds on the CP-violation parameter 2{beta}{sub s} using B{sub s}{sup 0} decays in which the flavor of the bottom meson at production is identified. The result is based on approximately 2,000 B{sub s}{sup 0} {yields} J/{psi}{phi} decays reconstructed in a 1.35 fb{sup -1} data sample collected with the CDFII detector using p{bar p} collisions produced at the Fermilab Tevatron. We report confidence regions in the two-dimensional space of 2{beta}{sub s} and the decay-width difference {Delta}{Lambda}. Assuming the Standard model predictions of 2{beta}{sub s} and {Delta}{Lambda}, the probability of a deviation as large as the level of the observed data is 15%, corresponding to 1.5 Gaussian Standard deviations.
Dongxiao Zhang - One of the best experts on this subject based on the ideXlab platform.
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A stochastic approach to nonlinear unconfined flow subject to multiple random fields
Stochastic Environmental Research and Risk Assessment, 2008Co-Authors: Jinzhong Yang, Dongxiao ZhangAbstract:In this study, the KLME approach, a moment-equation approach based on the Karhunen–Loeve decomposition developed by Zhang and Lu (Comput Phys 194(2):773–794, 2004), is applied to unconfined flow with multiple random inputs. The log-transformed hydraulic conductivity F, the recharge R, the Dirichlet boundary condition H, and the Neumann boundary condition Q are assumed to be Gaussian random fields with known means and covariance functions. The F, R, H and Q are first decomposed into finite series in terms of Gaussian Standard random variables by the Karhunen–Loeve expansion. The hydraulic head h is then represented by a perturbation expansion, and each term in the perturbation expansion is written as the products of unknown coefficients and Gaussian Standard random variables obtained from the Karhunen–Loeve expansions. A series of deterministic partial differential equations are derived from the stochastic partial differential equations. The resulting equations for uncorrelated and perfectly correlated cases are developed. The equations can be solved sequentially from low to high order by the finite element method. We examine the accuracy of the KLME approach for the groundwater flow subject to uncorrelated or perfectly correlated random inputs and study the capability of the KLME method for predicting the head variance in the presence of various spatially variable parameters. It is shown that the proposed numerical model gives accurate results at a much smaller computational cost than the Monte Carlo simulation.
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Stochastic uncertainty analysis for unconfined flow systems
Water Resources Research, 2006Co-Authors: Dongxiao Zhang, Zhiming LuAbstract:[1] A new stochastic approach proposed by Zhang and Lu (2004), called the Karhunen-Loeve decomposition-based moment equation (KLME), has been extended to solving nonlinear, unconfined flow problems in randomly heterogeneous aquifers. This approach is on the basis of an innovative combination of Karhunen-Loeve decomposition, polynomial expansion, and perturbation methods. The random log-transformed hydraulic conductivity field (lnKS) is first expanded into a series in terms of orthogonal Gaussian Standard random variables with their coefficients obtained as the eigenvalues and eigenfunctions of the covariance function of lnKS. Next, head h is decomposed as a perturbation expansion series Σh(m), where h(m) represents the mth-order head term with respect to the Standard deviation of lnKS. Then h(m) is further expanded into a polynomial series of m products of orthogonal Gaussian Standard random variables whose coefficients are deterministic and solved sequentially from low to high expansion orders using MODFLOW-2000. Finally, the statistics of head and flux are computed using simple algebraic operations on A series of numerical test results in 2-D and 3-D unconfined flow systems indicated that the KLME approach is effective in estimating the mean and (co)variance of both heads and fluxes and requires much less computational effort as compared to the traditional Monte Carlo simulation technique.
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conditional simulations of flow in randomly heterogeneous porous media using a kl based moment equation approach
Advances in Water Resources, 2004Co-Authors: Zhiming Lu, Dongxiao ZhangAbstract:Abstract In this study, we extend the KLME approach, a moment-equation approach based on the Karhunen–Loeve decomposition (KL), developed by Zhang and Lu [An efficient, higher-order perturbation approach for flow in randomly heterogeneous porous media via Karhunen–Loeve decomposition. J Comput Phys 2004;194(2):773–94] to efficiently incorporate existing direct measurements of the log hydraulic conductivity. We first decompose the conditional log hydraulic conductivity Y = lnKs as an infinite series on the basis of a set of orthogonal Gaussian Standard random variables {ξi}. The coefficients of this series are related to eigenvalues and eigenfunctions of the conditional covariance function of the log hydraulic conductivity. We then write head as an infinite series whose terms h(n) represent the head contribution at the nth order in terms of σY, the Standard deviation of Y, and derive a set of recursive equations for h(n). We assume that h(n) can be expressed as infinite series in terms of the products of n Gaussian random variables. The coefficients in these series are determined by substituting decompositions of Y and h(m), m σ Y 2 . The higher-order corrections for the conditional mean flux and flux covariance can be determined directly from the higher-order moments of the head, using Darcy’s law. We compare the results from the KLME approach against those from Monte Carlo (MC) simulations and the conventional first-order moment method. It is evident that the KLME approach with higher-order corrections is superior to the conventional first-order approximations and is computationally more efficient than both the Monte Carlo simulations and the conventional first-order moment method.
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An efficient, high-order perturbation approach for flow in random porous media via Karhunen-Loève and polynomial expansions
Journal of Computational Physics, 2004Co-Authors: Dongxiao Zhang, Zhiming LuAbstract:In this study, we attempt to obtain higher-order solutions of the means and (co)variances of hydraulic head for saturated flow in randomly heterogeneous porous media on the basis of the combination of Karhunen-Loeve decomposition, polynomial expansion, and perturbation methods. We first decompose the log hydraulic conductivity Y = ln Ks as an infinite series on the basis of a set of orthogonal Gaussian Standard random variables {ξi}. The coefficients of the series are related to eigenvalues and eigenfunctions of the covariance function of log hydraulic conductivity. We then write head as an infinite series whose terms h(n) represent head of nth order in terms of σY, the Standard deviation of Y, and derive a set of recursive equations for h(n). We then decompose h(n) with polynomial expansions in terms of the products of n Gaussian random variables. The coefficients in these series are determined by substituting decompositions of Y and h(n) into those recursive equations. We solve the mean head up to fourth-order in σY and the head variances up to third-order in σY2. We conduct Monte Carlo (MC) simulation and compare MC results against approximations of different orders from the moment-equation approach based on Karhunen-Loeve decomposition (KLME). We also explore the validity of the KLME approach for different degrees of medium variability and various correlation scales. It is evident that the KLME approach with higher-order corrections is superior to the conventional first-order approximations and is computationally more efficient than the Monte Carlo simulation.
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Higher-Order Approximations for Saturated Flow in Randomly Heterogeneous Media via Karhunen-Loéve Decomposition
World Water & Environmental Resources Congress 2003, 2003Co-Authors: Zhiming Lu, Dongxiao ZhangAbstract:In this study, we consider transient saturated flow in randomly heterogeneous porous media and try to obtain higher-order solutions of mean head and mean flux, as well as their associated uncertainties based on the combination of Karhunen-Loeve decomposition and perturbation methods. We first decompose the log hydraulic conductivity Y = lnKs as an infinite series on the basis of a set of orthogonal Gaussian Standard random variables. The coefficients of the series are related to eigenvalues and eigenfunctions of the covariance function of the log hydraulic conductivity. We then write head as an infinite series whose terms h (n) represent the hydraulic head of n th order in terms of σY, the Standard deviation of Y, and derive a set of recursive equations for h (n) . We assume that h (n) can be expressed as infinite series in terms of products of n Gaussian random variables. The coefficients in these series are determined by substituting decompositions of Ya nd h (n) into those recursive equations. We solve the mean head (and mean flux) up to fourth order in σY and the head (and flux) variances up to third order in σY 2 . We conduct Monte Carlo simulations (MC) and compare MC results against approximations of various orders from our moment-equation approach on the basis of Karhunen-Loeve decomposition (KLME). We also compare our results with those from first-order conventional moment-equation approach (CME). It is evident that the KLME approach with higher-order corrections is superior to firstorder approximations and is computationally more efficient than Monte Carlo simulations and the conventional moment-equation approach.
J Antos - One of the best experts on this subject based on the ideXlab platform.
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Measurement of the difference in CP-violating asymmetries in D0→K +K - and D0→π +π - decays at CDF
Physical Review Letters, 2012Co-Authors: T Aaltonen, S Amerio, A Anastassov, J Antos, B. Alvarez Gonzalez, Dante Amidei, Alberto Annovi, G. Apollinari, J. A. Appel, Tetsuo ArisawaAbstract:We report a measurement of the difference (D/Acp) between time-integrated-violating asymmetries in D{sup 0} K{sup +}K{sup -} and D{sup 0} {pi}{sup +}{pi}{sup -} decays reconstructed in the full data set of proton-antiproton collisions collected by the Collider Detector at Fermilab, corresponding to 9.7 fb{sup -1} of integrated luminosity. The strong decay D*{sup +} D{sup 0}{pi}{sup +} is used to identify the charm meson at production as D{sup 0} or ['D]{sup 0}. We measure D/Acp = (-0.62 0.21 /stat 0.10 /syst)%, which differs from zero by 2.7 Gaussian Standard deviations. This result supports similar evidence for violation in charm-quark obtained in proton-proton collisions.
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Measurement of theCP-violating phaseβsJ/ψϕinBs0→J/ψϕdecays with the CDF II detector
Physical Review D, 2012Co-Authors: T Aaltonen, S Amerio, D Amidei, A Anastassov, A Annovi, J Antos, B. Alvarez Gonzalez, G. Apollinari, J. A. Appel, T. ArisawaAbstract:We present a measurement of the CP-violating parameter βsJ/ψ using approximately 6500 Bs0→J/ψ decays reconstructed with the CDF II detector in a sample of pp collisions at √s=1.96TeV corresponding to 5.2fb -1 integrated luminosity produced by the Tevatron collider at Fermilab. We find the CP-violating phase to be within the range βsJ/ψ [0.02,0.52] [1.08,1.55] at 68% confidence level where the coverage property of the quoted interval is guaranteed using a frequentist statistical analysis. This result is in agreement with the Standard model expectation at the level of about one Gaussian Standard deviation. We consider the inclusion of a potential S-wave contribution to the Bs0→J/ψK +K - final state which is found to be negligible over the mass interval 1.009
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Observation of the Ωb- baryon and measurement of the properties of the Ξb- and Ωb- baryons
Physical Review D, 2009Co-Authors: T Aaltonen, J Adelman, T Akimoto, A Anastassov, J Antos, B. Alvarez Gonzalez, Silvia Amerio, Dante Amidei, Alberto Annovi, G. ApollinariAbstract:We report the observation of the bottom, doubly-strange baryon Ω ― b through the decay chain Ω ― b → J/ψΩ ― , where J/ψ → μ + μ ― , Ω ― → ΛK ― , and Λ → pπ ― , using 4.2 fb ―1 of data from pp collisions at s = 1.96 TeV, and recorded with the Collider Detector at Fermilab. A signal is observed whose probability of arising from a background fluctuation is 4.0 × 10 ―8 , or 5.5 Gaussian Standard deviations. The Ω ― b mass is measured to be 6054.4 ± 6.8(stat) ± 0.9(syst) MeV/c 2 . The lifetime of the Ω ― b baryon is measured to be 1.13 +0.53 ―0.40 (stat) ± 0.02(syst) ps. In addition, for the ― b baryon we measure a mass of 5790.9 ± 2.6(stat) ± 0.8(syst) MeV/c 2 and a lifetime of 1.56 ±0.27 ―0.25 (stat) ± 0.02(syst) ps. Under the assumption that the ― b and Ω ― b are produced with similar kinematic distributions to the Λ 0 b baryon, we find σ( ― b )B( ― b →J/ψ ― ) σ(Λ 0 b )B(Λ 0 b )→J/ψΛ) = 0.167 ±0.037 ―0.025 (stat) ± 0.012(syst) and σ(Ω ― b )B(Ω ― b →J/ψΩ ― ) σ(Λ 0 b )B(Λ 0 b →J/ψΛ) = 0.045 ±0.017 ―0.012 (stat) ± 0.004(syst) for baryons produced with transverse momentum in the range of 6―20 GeV/c.
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First Flavor-Tagged Determination of Bounds on Mixing-InducedCPViolation inBs0→J/ψϕDecays
Physical Review Letters, 2008Co-Authors: T Aaltonen, J Adelman, T Akimoto, S Amerio, D Amidei, A Anastassov, A Annovi, M. G. Albrow, B. Alvarez Gonzalez, J AntosAbstract:This Letter describes the first determination of bounds on the CP-violation parameter 2{beta}{sub s} using B{sub s}{sup 0} decays in which the flavor of the bottom meson at production is identified. The result is based on approximately 2,000 B{sub s}{sup 0} {yields} J/{psi}{phi} decays reconstructed in a 1.35 fb{sup -1} data sample collected with the CDFII detector using p{bar p} collisions produced at the Fermilab Tevatron. We report confidence regions in the two-dimensional space of 2{beta}{sub s} and the decay-width difference {Delta}{Lambda}. Assuming the Standard model predictions of 2{beta}{sub s} and {Delta}{Lambda}, the probability of a deviation as large as the level of the observed data is 15%, corresponding to 1.5 Gaussian Standard deviations.
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evidence for d0 d0 mixing using the cdf ii detector
Physical Review Letters, 2008Co-Authors: T Aaltonen, J Adelman, T Akimoto, M Albrow, S Amerio, D Amidei, A Anastassov, Alvarez B Gonzalez, A Annovi, J AntosAbstract:We measure the time dependence of the ratio of decay rates for the rare decay D0→K+π- to the Cabibbo-favored decay D0→K-π+. A signal of 12.7×103 D0→K+π- decays was obtained using the Collider Detector at Fermilab II detector at the Fermilab Tevatron with an integrated luminosity of 1.5 fb-1. We measure the D0-D 0 mixing parameters (RD,y′,x′2), and find that the data are inconsistent with the no-mixing hypothesis with a probability equivalent to 3.8 Gaussian Standard deviations.
A Anastassov - One of the best experts on this subject based on the ideXlab platform.
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Measurement of the difference in CP-violating asymmetries in D0→K +K - and D0→π +π - decays at CDF
Physical Review Letters, 2012Co-Authors: T Aaltonen, S Amerio, A Anastassov, J Antos, B. Alvarez Gonzalez, Dante Amidei, Alberto Annovi, G. Apollinari, J. A. Appel, Tetsuo ArisawaAbstract:We report a measurement of the difference (D/Acp) between time-integrated-violating asymmetries in D{sup 0} K{sup +}K{sup -} and D{sup 0} {pi}{sup +}{pi}{sup -} decays reconstructed in the full data set of proton-antiproton collisions collected by the Collider Detector at Fermilab, corresponding to 9.7 fb{sup -1} of integrated luminosity. The strong decay D*{sup +} D{sup 0}{pi}{sup +} is used to identify the charm meson at production as D{sup 0} or ['D]{sup 0}. We measure D/Acp = (-0.62 0.21 /stat 0.10 /syst)%, which differs from zero by 2.7 Gaussian Standard deviations. This result supports similar evidence for violation in charm-quark obtained in proton-proton collisions.
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Measurement of theCP-violating phaseβsJ/ψϕinBs0→J/ψϕdecays with the CDF II detector
Physical Review D, 2012Co-Authors: T Aaltonen, S Amerio, D Amidei, A Anastassov, A Annovi, J Antos, B. Alvarez Gonzalez, G. Apollinari, J. A. Appel, T. ArisawaAbstract:We present a measurement of the CP-violating parameter βsJ/ψ using approximately 6500 Bs0→J/ψ decays reconstructed with the CDF II detector in a sample of pp collisions at √s=1.96TeV corresponding to 5.2fb -1 integrated luminosity produced by the Tevatron collider at Fermilab. We find the CP-violating phase to be within the range βsJ/ψ [0.02,0.52] [1.08,1.55] at 68% confidence level where the coverage property of the quoted interval is guaranteed using a frequentist statistical analysis. This result is in agreement with the Standard model expectation at the level of about one Gaussian Standard deviation. We consider the inclusion of a potential S-wave contribution to the Bs0→J/ψK +K - final state which is found to be negligible over the mass interval 1.009
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Observation of the Ωb- baryon and measurement of the properties of the Ξb- and Ωb- baryons
Physical Review D, 2009Co-Authors: T Aaltonen, J Adelman, T Akimoto, A Anastassov, J Antos, B. Alvarez Gonzalez, Silvia Amerio, Dante Amidei, Alberto Annovi, G. ApollinariAbstract:We report the observation of the bottom, doubly-strange baryon Ω ― b through the decay chain Ω ― b → J/ψΩ ― , where J/ψ → μ + μ ― , Ω ― → ΛK ― , and Λ → pπ ― , using 4.2 fb ―1 of data from pp collisions at s = 1.96 TeV, and recorded with the Collider Detector at Fermilab. A signal is observed whose probability of arising from a background fluctuation is 4.0 × 10 ―8 , or 5.5 Gaussian Standard deviations. The Ω ― b mass is measured to be 6054.4 ± 6.8(stat) ± 0.9(syst) MeV/c 2 . The lifetime of the Ω ― b baryon is measured to be 1.13 +0.53 ―0.40 (stat) ± 0.02(syst) ps. In addition, for the ― b baryon we measure a mass of 5790.9 ± 2.6(stat) ± 0.8(syst) MeV/c 2 and a lifetime of 1.56 ±0.27 ―0.25 (stat) ± 0.02(syst) ps. Under the assumption that the ― b and Ω ― b are produced with similar kinematic distributions to the Λ 0 b baryon, we find σ( ― b )B( ― b →J/ψ ― ) σ(Λ 0 b )B(Λ 0 b )→J/ψΛ) = 0.167 ±0.037 ―0.025 (stat) ± 0.012(syst) and σ(Ω ― b )B(Ω ― b →J/ψΩ ― ) σ(Λ 0 b )B(Λ 0 b →J/ψΛ) = 0.045 ±0.017 ―0.012 (stat) ± 0.004(syst) for baryons produced with transverse momentum in the range of 6―20 GeV/c.
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First Flavor-Tagged Determination of Bounds on Mixing-InducedCPViolation inBs0→J/ψϕDecays
Physical Review Letters, 2008Co-Authors: T Aaltonen, J Adelman, T Akimoto, S Amerio, D Amidei, A Anastassov, A Annovi, M. G. Albrow, B. Alvarez Gonzalez, J AntosAbstract:This Letter describes the first determination of bounds on the CP-violation parameter 2{beta}{sub s} using B{sub s}{sup 0} decays in which the flavor of the bottom meson at production is identified. The result is based on approximately 2,000 B{sub s}{sup 0} {yields} J/{psi}{phi} decays reconstructed in a 1.35 fb{sup -1} data sample collected with the CDFII detector using p{bar p} collisions produced at the Fermilab Tevatron. We report confidence regions in the two-dimensional space of 2{beta}{sub s} and the decay-width difference {Delta}{Lambda}. Assuming the Standard model predictions of 2{beta}{sub s} and {Delta}{Lambda}, the probability of a deviation as large as the level of the observed data is 15%, corresponding to 1.5 Gaussian Standard deviations.
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evidence for d0 d0 mixing using the cdf ii detector
Physical Review Letters, 2008Co-Authors: T Aaltonen, J Adelman, T Akimoto, M Albrow, S Amerio, D Amidei, A Anastassov, Alvarez B Gonzalez, A Annovi, J AntosAbstract:We measure the time dependence of the ratio of decay rates for the rare decay D0→K+π- to the Cabibbo-favored decay D0→K-π+. A signal of 12.7×103 D0→K+π- decays was obtained using the Collider Detector at Fermilab II detector at the Fermilab Tevatron with an integrated luminosity of 1.5 fb-1. We measure the D0-D 0 mixing parameters (RD,y′,x′2), and find that the data are inconsistent with the no-mixing hypothesis with a probability equivalent to 3.8 Gaussian Standard deviations.