4,032 research outputs found

    Role of Charm Factory in Extracting CKM-Phase Information via B --> DK

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    In this paper we study the impact of data that can be obtained from a Charm Factory on the determination of the CKM parameter gamma from decays of the form B -> D0 K where the D0 decays to specific inclusive and exclusive final states. In particular, for each exclusive final state ff, the charm factory can determine the strong phase difference between D0-> f and D0-bar -> f by exploiting correlations in psi(3770)-> D0 D0-bar. This provides crucial input to the determination of gamma via the interference of B+- -> K+- D0 -> f with B+- -> K+- D0-bar -> f. We discuss how the method may be generalized to inclusive final states and illustrate with a toy model how such methods may offer one of the best means to determine gamma with 10^8-10^9 B-mesons.Comment: 12 pages, 7 figures, Version 2: Fixed typos; add reference; Version 3: fixed latex glitc

    Getting beta-alpha without penguins

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    Oscillation effects in B0 -> Ks D0 and related processes are considered to determine delta=beta-alpha+pi. We suggest that D0 decays to CP eigenstates used in concert with inclusive D0 decays provide a powerful method for determining delta cleanly i.e. without any complication from penguin processes. The CP asymmetry is expected to be <=40% for D0 decays to non-CP eigenstates and <=80% for decays to CP eigenstates. This method can lead to a fairly accurate determination of delta with O(10^8-10^9) B-mesons.Comment: 4 pages 1 figure; Version 2: minor changes; references added; Some changes in response to Referee Comment

    CP Nonconservation in e+ettˉge^+e^-\to t\bar tg

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    CP violation effects in e+ettˉge^+ e^- \to t\bar tg are examined. CP-odd, TnT_n-odd and TnT_n-even observables can both be used to extract information on the real and imaginary parts of Feynman amplitudes. Two Higgs doublet model with CP violating phase from neutral Higgs exchange is used to estimate possible effects.Comment: 9 pages, 4 Figures, Late

    Fermi Space Telescope highlights

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    The Fermi Space Mission has had a remarkable first two years of operation in low-Earth orbit, collecting over 380 million events, and revealing unprecedented details of the gamma-ray sky. The Large Area Telescope (LAT) has lived up to expectations. Being the first all-sky monitor in almost real time has revealed a wealth of transient phenomena. Some highlights of the discoveries made by the Fermi-LAT in the past two years are presented. Possible future directions for this highly successful mission will be discussed

    A Comparison of Two Methods of Teaching Mathematics: Manipulative and Conventional.

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    This study was designed to provide information on the use of manipulatives in an elementary school mathematics curriculum. The primary goal was to determine if there was a significant difference in student achievement in mathematics at the third grade level when selected mathematics concepts are taught through the use of manipulatives compared to the use of conventional textbooks and worksheets. The sample in this study consisted of one third grade class from a small school in a community of approximately six thousand people. This class of twenty-four students, eleven girls and thirteen boys was taught by the researcher. The class was divided into two matched groups based on information from a standardized achievement test and a textbook pretest over selected math concepts. The experimental group used manipulatives to master the lesson objectives. The control group used the conventional textbook and worksheet pages to master the lesson objectives. A post test published by the Heath Mathematics Company was administered to both groups to see if there was a significant difference in student achievement. Analysis of the data through use of a t-test showed a significant difference to the .001 level of confidence in student achievement in third grade mathematics with the experimental group producing higher scores than the control group. The findings from this limited study support the use of manipulatives as a supplement to the third grade mathematics curriculum

    Bounds on charged higgs boson in the 2HDM type III from Tevatron

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    We consider the Two Higgs Doublet Model (2HDM) of type III which leads to Flavour Changing Neutral Currents (FCNC) at tree level. In the framework of this model we can use an appropriate form of the Yukawa Lagrangian that makes the type II model limit of the general type III couplings apparent. This way is useful in order to compare with the experimental data which is model dependent. The analytical expressions of the partial width Γ(tH+b)\Gamma (t \to H^+ b) are derived and we compare with the data available at this energy range. We examine the limits on the new parameters λij\lambda_{ij} from the validness of perturbation theory.Comment: 14 pages, 4 figures, Universidad Nacional de Colombia. typos correcte

    CP Nonconservation in ppˉtbˉXp\bar p\to t\bar b X at the Tevatron

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    The reaction ppˉtbˉXp\bar p\to t\bar bX is found to be rather rich in exhibiting several different types of CP asymmetries. The spin of the top quark plays an important role. Asymmetries are related to form factors arising from radiative corrections of the tbWtbW production vertex due to non-standard physics. As illustrations, effects are studied in two Higgs Doublet Models and in Supersymmetric Models; asymmetries up to a few percent may be possible.Comment: 14 pages, 3 figures. Note: replaced due to minor problems that appeared on some postscript previewers. No change in conten
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