821 research outputs found

    Lepton polarization correlations in BKττ+B \to K^* \tau^- \tau^+

    Get PDF
    In this work we will study the polarizations of both leptons (τ\tau) in the decay channel BKττ+B\to K^* \tau^- \tau^+. In the case of the dileptonic inclusive decay BK+B\to K^* \ell^- \ell^+, where apart from the polarization asymmetries of single lepton \ell, one can also observe the polarization asymmetries of both leptons simultaneously. If this sort of measurement is possible then we can have, apart from decay rate, FB asymmetry and the six single lepton polarization asymmetries (three each for \ell^- and +\ell^+), nine more double polarization asymmetries. This will give us a very useful tool in more strict testing of SM and the physics beyond. We discuss the double polarization asymmetries of τ\tau leptons in the decay mode BKττ+B\to K^* \tau^- \tau^+ within the SM and the Minimal Supersymmetric extensions of it.Comment: 21 pages, 21 figures; version to match paper to appear in PR

    Analysis of the semileptonic (B_c -> B_u* l+ l-) decay from QCD sum rules

    Full text link
    We analyze the semileptonic (B_c -> B_u* l+ l-) decay in the frame work of the Standard Model. We calculate the (B_c) to (B_u*) transition form factors in QCD sum rules. Analytical expressions for the spectral densities and gluon condensates are presented. The branching ratio of the (B_c -> B_u* l+ l-) decay is calculated, and it is obtained that this decay can be detectable at forthcoming LHC machines.Comment: 17 pages, no figures, LaTeX formatte

    Evaluation of angiotensin II receptor blockers for drug formulary using objective scoring analytical tool

    Get PDF
    Drug selection methods with scores have been developed and used worldwide for formulary purposes. These tools focus on the way in which the products are differentiated from each other within the same therapeutic class. Scoring Analytical Tool (SAT) is designed based on the same principle with score and is able to assist formulary committee members in evaluating drugs either to add or delete in a more structured, consistent and reproducible manner. Objective: To develop an objective SAT to facilitate evaluation of drug selection for formulary listing purposes. Methods: A cross-sectional survey was carried out. The proposed SAT was developed to evaluate the drugs according to pre-set criteria and sub-criteria that were matched to the diseases concerned and scores were then assigned based on their relative importance. The main criteria under consideration were safety, quality, cost and efficacy. All these were converted to questionnaires format. Data and information were collected through self-administered questionnaires that were distributed to medical doctors and specialists from the established public hospitals. A convenient sample of 167 doctors (specialists and non-specialists) were taken from various disciplines in the outpatient clinics such as Medical, Nephrology and Cardiology units who prescribed ARBs hypertensive drugs to patients. They were given a duration of 4 weeks to answer the questionnaires at their convenience. One way ANOVA, Kruskal Wallis and post hoc comparison tests were carried out at alpha level 0.05. Results: Statistical analysis showed that the descending order of ARBs preference was Telmisartan or Irbesartan or Losartan, Valsartan or Candesartan, Olmesartan and lastly Eprosartan. The most cost saving ARBs for hypertension in public hospitals was Irbesartan. Conclusion: SAT is a tool which can be used to reduce the number of drugs and retained the most therapeutically appropriate drugs in the formulary, to determine most cost saving drugs and has the potential to complement the conventional method of drug selection as it is effective in aiding decision making process through the pre-established criteria and increasing scientific ground of decisions and transparency.Scopu

    General analysis of time evolution of decay spectrum in B^0 -> pi^+ pi^- l^+ l^-

    Full text link
    Using the general, model independent form of effective Hamiltonian, the decay spectrum of B^0 -> pi^+ pi^- l^+ l^- decay is studied. The sensitivity of experimentally measurable asymmetries to the new Wilson coefficients and time is studied. It is observed that different asymmetries are sensitive to the new Wilson coefficients and they can serve as an efficient tool for establishing new physics beyond SM.Comment: 15 pp, 4 figures (postscript formatted), LaTex formatte

    B--> K^* l^+ l^- decay in the two Higgs doublet model with flavor changing neutral currents

    Full text link
    We study the decay width, forward-backward asymmetry and the longitudinal lepton polarization for the exclusive decay B --> K^* l^+ l^- in the two Higgs doublet model with three level flavor changing neutral currents (model III) and analyse the dependencies of these quantities on the the selected parameters, \xi^{U,D}, of model III including the next to leading QCD corrections. It is found that to look for charged Higgs effects, the measurements of the branching ratio, forward-backward asymmetry and the longitudinal lepton polarization for the decay B --> K^* l^+ l^- are promising.Comment: 17 pages, 6 figure

    Exclusive B -> K^* l^+ l^- decay with polarized K^* and new physics effects

    Get PDF
    Using the most general, model independent effective Hamiltonian, the branching ratio of the (B -> K^* l^+ l^-) decay, when K^* meson is longitudinally or transversally polarized, is presented. The dependence of the branching ratio on the new Wilson coefficients, when K^* meson is polarized, is studied. It is observed that the branching ratio is very sensitive to the vector and tensor type interactions, which will be useful in search of new physics beyond the Standard Model.Comment: 13 pp, 6 figures (postscript formatted), LaTex formatte

    Analysis of Various Polarization Asymmetries In The Inclusive bs+b\to s \ell^+ \ell^- Decay In The Fourth-Generation Standard Model

    Get PDF
    In this study a systematical analysis of various polarization asymmetries in inclusive b \rar s \ell^+ \ell^- decay in the standard model (SM) with four generation of quarks is carried out. We found that the various asymmetries are sensitive to the new mixing and quark masses for both of the μ\mu and τ\tau channels. Sizeable deviations from the SM values are obtained. Hence, b \rar s \ell^+ \ell^- decay is a valuable tool for searching physics beyond the SM, especially in the indirect searches for the fourth-generation of quarks (t,b)t', b').Comment: 19 Pages, 10 Figures, 3 Table

    Lepton polarization and CP-violating effects in "B -> K^* tau^+ tau^-" decay in standard and two Higgs doublet models

    Full text link
    The most general model independent expressions for the CP-violating asymmetry, longitudinal, transversal and normal polarizations of leptons are derived. Application of these general results to the concrete models such as Standard model and three different types of two Higgs doublet model is discussed.Comment: 18 pages, 8 postscripted figure

    General analysis of lepton polarizations in rare B -> K^* l^+ l^- decay beyond the standard model

    Get PDF
    The general analysis of lepton polarization asymmetries in rare B -> K^* l^+ l^- decay is investigated. Using the most general, model independent effective Hamiltonian, the general expressions of the longitudinal, normal and transversal polarization asymmetries for l^- and l^+ and combinations of them are presented. The dependence of lepton polarizations and their combinations on new Wilson coefficients are studied in detail. Our analysis shows that the lepton polarization asymmetries are very sensitive to the scalar and tensor type interactions, which will be very useful in looking for new physics beyond the standard model.Comment: 29 pp, 15 figure

    Fourth generation effects in rare exclusive B -> K^* l^+ l^- decay

    Get PDF
    Influence of the fourth generation, if ever exists, on the experimentally measurable quantities such as invariant dilepton mass distribution, lepton forward-backward asymmetry, and the ratio (Gamma_L/Gamma_T) of the decay widths when K* meson is longitudinally and transversally polarized, is studied. Using the experimental results on the branching ratios for the (B -> X_s) gamma and semileptonic (B -> X_c l nu) decays, the two possible solutions of the 4x4 Cabibbo-Kobayashi-Maskawa factor (V_{t's} V_{t^'b}) are obtained as a function of the t'-quark mass. It is observed that the results for the above-mentioned physical quantities are essentially different from the standard model predictions only for one solution of the CKM factor. In this case the above-mentioned physical quantities can serve as efficient tools in search of the fourth generation. The other solution yields almost identical results with the SM.Comment: 19 pages, 10 postscripted figures, LaTeX formatte
    corecore