139 research outputs found

    Effects of Symmetry Breaking on the Strong and Electroweak Interactions of the Vector Nonet

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    Starting from a chiral invariant and quark line rule conserving Lagrangian of pseudoscalar and vector nonets we introduce first and second order symmetry breaking as well as quark line rule violating terms and fit the parameters, at tree level, to many strong and electroweak processes. A number of predictions are made. The electroweak interactions are included in a manifestly gauge invariant manner. The resulting symmetry breaking pattern is discussed in detail. Specifically, for the ``strong'' interactions, we study all the vector meson masses and V -> \phi \phi decays, including isotopic spin violations. In the electroweak sector we study the { rho^0 , omega , phi } -> e^+e^- decays, { pi^+ , K^+ , K^0 } ``charge radii'', K_{l3} ``slope factor'' and the overall e^+e^- -> pi^+ pi^- process. It is hoped that the resulting model may be useful as a reasonable description of low energy physics in the range up to about 1 GeV.Comment: 43 pages (LaTeX), 5 PostScript figures are included as uuencoded-compressed-tar file at the en

    Short and long distance contributions to B→K∗γγB \to K^* \gamma \gamma

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    We study the decay of the neutral B meson to K∗γγK^* \gamma \gamma within the framework of the Standard Model, including long distance contributions.Comment: 14 pages, 2 figures; A sign error in the numerical estimation corrected. Results and figures changed. Results for resonance contributions also updated to match with the experimetal values in the narrow width approximatio

    Effect of FCNC mediated Z boson on lepton flavor violating decays

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    We study the three body lepton flavor violating (LFV) decays Ό−→e−e+e−\mu^- \to e^- e^+ e^-, τ−→li−lj+lj−\tau^- \to l_i^- l_j^+ l_j^- and the semileptonic decay τ→Όϕ\tau \to \mu \phi in the flavor changing neutral current (FCNC) mediated ZZ boson model. We also calculate the branching ratios for LFV leptonic B decays, Bd,s→ΌeB_{d,s} \to \mu e, Bd,s→τeB_{d,s} \to \tau e, Bd,s→τΌB_{d,s} \to \tau \mu and the conversion of muon to electron in Ti nucleus. The new physics parameter space is constrained by using the experimental limits on Ό−→e−e+e−\mu^- \to e^- e^+ e^- and τ−→Ό−Ό+Ό−\tau^- \to \mu^- \mu^+ \mu^-. We find that the branching ratios for τ→eee\tau \to eee and τ→Όϕ\tau \to \mu \phi processes could be as large as ∌O(10−8)\sim {\cal O}(10^{-8}) and BrBd,s→τΌ,τe)∌O(10−10){\rm Br}B_{d,s} \to \tau \mu, \tau e) \sim {\cal O}(10^{-10}). For other LFV B decays the branching ratios are found to be too small to be observed in the near future.Comment: 15 pages, 8 figures, typos corrected, one more section added, version to appear in EPJ

    A Systematic Analysis of the Lepton Polarization Asymmetries in the Rare B Decay, B -> X_s\tau^+\tau^-

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    The most general model-independent analysis of the lepton polarization asymmetries in the rare B decay, \Bstt, is presented. We present the longitudinal, normal and transverse polarization asymmetries for the τ+\tau^+ and τ−\tau^-, and combinations of them, as functions of the Wilson coefficients of twelve independent four-Fermi interactions, ten of them local and two nonlocal. These procedures will tell us which type of operators contributes to the process. And it will be very useful to pin down new physics systematically, once we have the experimental data with high statistics and a deviation from the Standard Model is found.Comment: 24 pages, 8 figures, LaTe

    Model Independent Analysis of the Forward-Backward Asymmetry for the B→K1ÎŒ+Ό−B\to K_{1}\mu^{+}\mu^{-} Decay

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    The sensitivity of the zero position of the forward backward asymmetry AFB\mathcal{A}_{FB} for the exclusive B→K1(1270)ÎŒ+Ό−B\rightarrow K_{1}(1270)\mu^{+}\mu^{-} decay is examined by using most general non-standard 4-fermion interactions. Our analysis shows that the zero position of the forward backward asymmetry is very sensitive to the sign and size of the Wilson coefficients corresponding to the new vector type interactions, which are the counter partners of the usual Standard Model operators but have opposite chirality. In addition to these, the other significant effect comes from the interference of Scalar-Pseudoscalar and Tensor type operators. These results will not only enhance our theoretical understanding about the axial vector mesons but will also serve as a good tool to look for physics beyond the SM.Comment: 14 pages, 8 figures, Published version that appears in EPJ

    Lepton polarization correlations in B→K∗τ−τ+B \to K^* \tau^- \tau^+

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    In this work we will study the polarizations of both leptons (τ\tau) in the decay channel B→K∗τ−τ+B\to K^* \tau^- \tau^+. In the case of the dileptonic inclusive decay B→K∗ℓ−ℓ+B\to K^* \ell^- \ell^+, where apart from the polarization asymmetries of single lepton ℓ\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 ℓ−\ell^- and ℓ+\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 B→K∗τ−τ+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

    The Forward Backward asymmetries of B→Xsτ+τ−B \to X_s \tau^+ \tau^- in the MSSM

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    The relatively clean theoretical probes of the Standard Model (SM), and the various theories beyond the SM, provided by radiative, semi-leptonic and (purely) leptonic decays of B-mesons have become increasingly important. Due to the large number of possible distributions in the semi-leptonic decays based on the quark level transition b→sℓ+ℓ−b \to s \ell^+ \ell^- (not just the branching ratio), these transitions have become very useful. A study of the Forward-Backward asymmetries for the inclusive decay (B→Xsℓ+ℓ−B \to X_s \ell^+ \ell^-) is carried out in this paper. This study shall be performed in the SM and a minimal supersymmetric extensions of the SM, namely the mSUGRA model.Comment: 14 pages, 4 figures (5 eps files); modified to JHEP format, accepted in JHEP, references adde

    Supersymmetric effects on Forward Backward asymmetries of B→Kℓ+ℓ−B \to K \ell^+ \ell^-

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    Leptonic and semi-leptonic rare decays of B-mesons are very clean (both theoretically and experimentally) signatures of any new physics beyond the Standard Model (SM). More specifically the decay \btokll has been theoretically observed to be very sensitive to new physics as the Forward Backward (FB) asymmetry in this decay mode vanishes in the SM. Supersymmetry, however, predicts a non-vanishing value of this asymmetry. In this work we will study the polarized lepton pair FB asymmetry, i.e. the FB asymmetry of the lepton when one (or both) final state lepton(s) are polarized. We will study these asymmetries both within the SM and for Supersymmetric corrections to the SM.Comment: 18 pages, RevTeX file including 21 eps figures; version accepted for publication in Phys. Rev. D. Some references adde

    Extracorporeal Life Support Organization (ELSO): guidelines for pediatric cardiac failure

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    These guidelines are applicable to neonates and children with cardiac failure as indication for extracorporeal life support. These guidelines address patient selection, management during extracorporeal membrane oxygenation, and pathways for weaning support or bridging to other therapies. Equally important issues, such as personnel, training, credentialing, resources, follow-up, reporting, and quality assurance, are addressed in other Extracorporeal Life Support Organization documents or are center-specific.Perioperative Medicine: Efficacy, Safety and Outcome (Anesthesiology/Intensive Care
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