1,580 research outputs found

    CP Violating Rate Difference Relations for BPPB\to PP and BPVB \to PV in Broken SU(3)

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    Within the standard model there exist certain relations between CP violating rate differences in B decays in the SU(3) limit. We study SU(3) breaking corrections to these relations in the case of charmless, hadronic, two body BB decays using the improved factorization model of Ref.\cite{3}. We consider the cases BPPB \to PP and BPVB \to PV for both BdB_d and BsB_s mesons. We present an estimate for ACP(ππ+)A_{CP}(\pi^- \pi^+) in terms of ACP(Kπ+)A_{CP}(K^- \pi^+).Comment: Latex 13 pages, no figure

    Determination of the magnetic susceptibility of the quark condensate using radiative heavy meson decays

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    We use a light-cone sum rule (LCSR) analysis of the branching ratios of radiative meson decays to contrain the value of the magnetic susceptibility of the quark condensate χ(μ)\chi(\mu). For the first time, we use a complete set of three-particle distribution amplitudes that enables us to give a consistent prediction for the branching ratios. Furthermore we will make use of a very recent update of several non-perturbative parameters. Our final result for χ(μ=1GeV)=2.85±0.5GeV2\chi(\mu= 1 {\rm GeV})= 2.85 \pm 0.5 {\rm GeV}^{-2} (assuming asymptotic wave functions) agrees with the currently used value of 3.15±0.3GeV23.15 \pm 0.3 {\rm GeV}^{-2}.Comment: 21 pages, 4 figures, references adde

    The Semileptonic Decays Dπ(ρ)eνD\to \pi(\rho) e \nu and Bπ(ρ)eνB\to \pi (\rho) e \nu from QCD Sum Rules

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    We investigate the semileptonic decays of B and D mesons into π\pi and ρ\rho mesons, respectively, by means of QCD sum rules. We find that for the vector formfactors involved the pole dominance hypothesis is valid to good accuracy with pole masses in the expected range. Pole dominance, however, does not apply to the axial formfactors which results in specific predictions for the predominant polarization of the ρ\rho meson and the shape of the lepton spectrum. For the total decay rates we find Γ(Bˉ0π+eνˉ)=(5.1±1.1)Vub21012s1\Gamma (\bar B^0 \to \pi^+ e^- \bar\nu) = (5.1\pm 1.1)\,|V_{ub}|^2\, 10^{12}\,{\rm s^{-1}}, Γ(D0πe+ν)=(8.0±1.7)Vcd21010s1\Gamma ( D^0 \to \pi^- e^+ \nu) = (8.0\pm 1.7)\,|V_{cd}|^2\, 10^{10}\,{\rm s^{-1}}, Γ(Bˉ0ρ+eνˉ)=(1.2±0.4)Vub21013s1\Gamma (\bar B^0 \to \rho^+ e^- \bar\nu) = (1.2\pm 0.4\,)\,|V_{ub}|^2\, 10^{13}\,{\rm s^{-1}} and Γ(D0ρe+ν)=(2.4±0.7)Vcd2109s1\Gamma (D^0 \to \rho^- e^+\nu) = (2.4\pm 0.7)\,|V_{cd}|^2\, 10^{9}\,{\rm s^{-1}}.Comment: 23 pages, 12 figures included as uu-encoded file, needs REVTEX, TUM--T31--39/9

    Light-cone sum rules for BπB \to \pi form factors revisited

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    We reconsider and update the QCD light-cone sum rules for BπB\to \pi form factors. The gluon radiative corrections to the twist-2 and twist-3 terms in the correlation functions are calculated. The MSˉ\bar{MS} bb-quark mass is employed, instead of the one-loop pole mass used in the previous analyses. The light-cone sum rule for fBπ+(q2)f^+_{B\pi}(q^2) is fitted to the measured q2q^2-distribution in BπlνlB\to \pi l \nu_l, fixing the input parameters with the largest uncertainty: the Gegenbauer moments of the pion distribution amplitude. For the BπB\to \pi vector form factor at zero momentum transfer we predict fBπ+(0)=0.260.03+0.04f^+_{B\pi}(0)= 0.26^{+0.04}_{-0.03}. Combining it with the value of the product VubfBπ+(0)|V_{ub}f^+_{B\pi}(0)| extracted from experiment, we obtain Vub=(3.5±0.4±0.2±0.1)×103|V_{ub}|=(3.5\pm 0.4\pm 0.2\pm 0.1) \times 10^{-3}. In addition, the scalar and penguin BπB\to \pi form factors fBπ0(q2)f^0_{B\pi}(q^2) and fBπT(q2)f^T_{B\pi}(q^2) are calculated.Comment: 33 pages, 7 figures, one figure and a few comments added, version to appear in JHE

    Next--to--Leading Order Corrections to Meson Masses in the Heavy Quark Effective Theory

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    We use the QCD sum rule approach to calculate the splitting between vector and pseudoscalar mesons containing one light and one heavy quark, and the kinetic energy of the heavy quark. Our result for the splitting induced by the chromomagnetic interaction agrees to the experimental data on charm and beauty mesons. For the matrix element of the kinetic energy operator, we obtain the value K=(0.60±0.10)GeV2K=-(0.60\pm 0.10)\, {\rm GeV}^2.Comment: 33 ps., PS figures included, requires REVTEX.3 and psfig, TUM-T31-42/93/R (additional contribution to kinetic energy taken into account, marginal changes in the results

    Column reduced rational matrix functions with given null-pole data in the complex plane

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    AbstractExplicit formulas are given for rational matrix functions which have a prescribed null-pole structure in the complex plane and are column reduced at infinity. A full parametrization of such functions is obtained. The results are specified and developed further for matrix polynomials

    Analysis of the vertexes ΞQΞQV\Xi_Q^*\Xi'_Q V, ΣQΣQV\Sigma_Q^*\Sigma_Q V and radiative decays ΞQΞQγ\Xi_Q^*\to \Xi'_Q \gamma, ΣQΣQγ\Sigma_Q^*\to \Sigma_Q \gamma

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    In this article, we study the vertexes ΞQΞQV\Xi_Q^*\Xi'_Q V and ΣQΣQV\Sigma_Q^* \Sigma_Q V with the light-cone QCD sum rules, then assume the vector meson dominance of the intermediate ϕ(1020)\phi(1020), ρ(770)\rho(770) and ω(782)\omega(782), and calculate the radiative decays ΞQΞQγ\Xi_Q^*\to \Xi'_Q \gamma and ΣQΣQγ\Sigma_Q^*\to \Sigma_Q \gamma.Comment: 28 pages, 4 tables, revised versio

    Strong Couplings of Heavy Mesons to A Light Vector Meson in QCD

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    We make a detailed analysis of the BBρ(DDρ)BB\rho(DD\rho) and BBρ(DDρ)B^*B\rho(D^{*}D\rho) strong couplings gBBρ(gDDρ)g_{BB\rho}(g_{DD\rho}) and gBBρ(gDDρ)g_{B^*B\rho}(g_{D^{*}D\rho}) using QCD light cone sum rules(LCSR). The existing some negligence is pointed out in the previous LCSR calculation on gBBρ(gDDρg_{B^*B\rho} (g_{D^{\ast}D\rho}) and an updated estimate is presented. Our findings can be used to understand the behavior of the B,DρB,D \to \rho semileptonic form factors at large momentum transitions.Comment: 15 pages, latex, 2 figures, version appearing in PRD, typos correcte

    Analysis of the vertices DDVDDV and DDVD^*DV with light-cone QCD sum rules

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    In this article, we study the vertices DDVDDV and DDVD^*DV with the light-cone QCD sum rules. The strong coupling constants gDDVg_{DDV} and fDDVf_{D^*DV} play an important role in understanding the final-state re-scattering effects in the hadronic B decays. They are related to the basic parameters β\beta and λ\lambda respectively in the heavy quark effective Lagrangian, our numerical values are smaller than the existing estimations.Comment: 16 pages, 6 figures, revised versio

    Flavour SU(3) Symmetry in Charmless B Decays

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    QCD sum rules are used to estimate the flavour SU(3)-symmetry violation in two-body B decays to pions and kaons. In the factorizable amplitudes the SU(3)-violation manifests itself in the ratio of the decay constants f_K/f_pi and in the differences between the B->K, B_s->K and B->pi form factors. These effects are calculated from the QCD two-point and light-cone sum rules, respectively, in terms of the strange quark mass and the ratio of the strange and nonstrange quark-condensate densities. Importantly, QCD sum rules predict that SU(3) breaking in the heavy-to-light form factors can be substantial and does not vanish in the heavy-quark mass limit. Furthermore, we investigate the strange-quark mass dependence of nonfactorizable effects in the B->K pi decay amplitudes. Taking into account these effects we estimate the accuracy of several SU(3)-symmetry relations between charmless B-decay amplitudes.Comment: Two references added, version to be published in Phys.Rev.D, 21 pages, 12 postscript figure
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