355 research outputs found

    Chiral Lagrangian with higher resonances and flavour SU(3) SU(3) breaking

    Full text link
    A chiral Lagrangian with SU(3) SU(3) breaking and higher resonances is proposed. In this model, the SU(3) SU(3) breaking structure in vector-pseudoscalar sector is realized with the decay constants of pseudoscalar mesons and the masses of vector mesons used as inputs. We examine whether the resulting SU(3) SU(3) breaking effect in the charge radii of pseudoscalar mesons is consistent with the experimental facts.Comment: 29 pages, REVTEX(ver.3), DPNU-93-3

    Semileptonic B(Bs,Bc)B(B_s, B_c) decays in the light-cone QCD sum rules

    Full text link
    Semileptonic BB(Bs,BcB_s, B_c) decays are investigated systematically in the light-cone QCD sum rules. Special emphasis is put on the LCSR calculation on weak form factors with an adequate chiral current correlator, which turns out to be particularly effective to control the pollution by higher twist components of spectator mesons. The result for each channel depends on the distribution amplitude of the the producing meson. The leading twist distribution amplitudes of the related heavy mesons and charmonium are worked out by a model approach in the reasonable way. A practical scenario is suggested to understand the behavior of weak form factors in the whole kinematically accessible ranges. The decay widths and branching ratios are estimated for several BB(BcB_c) decay modes of current interest.Comment: 8 pages, talk given by the first arthur at 4th International Conference on Flavor Physics (ICFP 2007), Beijing, China, Sept 24-28, 200

    Nonfactorizable contributions to BD()MB \to D^{(*)} M decays

    Full text link
    While the factorization assumption works well for many two-body nonleptonic BB meson decay modes, the recent measurement of BˉD()0M0\bar B\to D^{(*)0}M^0 with M=πM=\pi, ρ\rho and ω\omega shows large deviation from this assumption. We analyze the BD()MB\to D^{(*)}M decays in the perturbative QCD approach based on kTk_T factorization theorem, in which both factorizable and nonfactorizable contributions can be calculated in the same framework. Our predictions for the Bauer-Stech-Wirbel parameters, a2/a1=0.43±0.04|a_2/a_1|= 0.43\pm 0.04 and Arg(a2/a1)42Arg(a_2/a_1)\sim -42^\circ and a2/a1=0.47±0.05|a_2/a_1|= 0.47\pm 0.05 and Arg(a2/a1)41Arg(a_2/a_1)\sim -41^\circ, are consistent with the observed BDπB\to D\pi and BDπB\to D^*\pi branching ratios, respectively. It is found that the large magnitude a2|a_2| and the large relative phase between a2a_2 and a1a_1 come from color-suppressed nonfactorizable amplitudes. Our predictions for the Bˉ0D()0ρ0{\bar B}^0\to D^{(*)0}\rho^0, D()0ωD^{(*)0}\omega branching ratios can be confronted with future experimental data.Comment: 25 pages with Latex, axodraw.sty, 6 figures and 5 tables, Version published in PRD, Added new section 5 and reference

    The transition form factors for semi-leptonic weak decays of J/ψJ/\psi in QCD sum rules

    Full text link
    Within the Standard Model, we investigate the semi-leptonic weak decays of J/ψJ/\psi. The various form factors of J/ψJ/\psi transiting to a single charmed meson (D(d,s)()D^{(*)}_{(d,s)}) are studied in the framework of the QCD sum rules. These form factors fully determine the rates of the weak semi-leptonic decays of J/ψJ/\psi and provide valuable information about the non-perturbative QCD effects. Our results indicate that the decay rate of the semi-leptonic weak decay mode J/ψDs()+e++νeJ/\psi \to D^{(*)-}_{s}+e^{+}+\nu_{e} is at order of 101010^{-10}.Comment: 28 pages, 6 figures, revised version to be published in Eur.Phys.J.

    Analysis of Supersymmetric Effects on B -> phi K Decays in the PQCD Approach

    Full text link
    We study the effects of the MSSM contribution on B -> phi K decays using the perturbative QCD approach. In this approach, strong phases can be calculated, so that we can predict the values of CP asymmetries with the MSSM contribution. We predict a large relative strong phase between the penguin amplitude and the chromomagnetic penguin amplitude. If there is a new CP violating phase in the chromomagnetic penguin amplitude, then the CP asymmetries may change significantly from the SM prediction. We parametrize the new physics contributions that appear in the Wilson coefficients. We maximize the new physics parameters up to the point where it is limited by experimental constraints. In the case of the LR insertion, we find that the direct CP asymmetries can reach about 85% and the indirect CP asymmetry can reach about -30%.Comment: 18 pages, 9 figures, REVTeX, Minor changes, Version to appear in Phys. Rev.

    Possible Large Direct CP Violations in Charmless B-Decays

    Get PDF
    We discuss the perturbative QCD approach for the exclusive two body B-meson decays to light mesons. We briefly review its ingredients and some important theoretical issues on factorization approach. We show numerical results which are compatible with present experimantal data for the charmless B-meson decays. Specailly we predict the possibility of large direct CP violation effects in B0π+πB^0 \to \pi^{+}\pi^{-} (23±7(23\pm7 %) and B0K+πB^0\to K^{+}\pi^{-} (17±5(-17\pm5%). In the last section we investigate two methods to determine the weak phases ϕ2\phi_2 and ϕ3\phi_3 from Bππ,KπB \to \pi\pi,K\pi processes. We obtain bounds on ϕ2\phi_2 and ϕ3\phi_3 from present experimental measurements.Comment: 18 pages, latex, 8 figures and 8 tables, typos corrected and added more tables and references. Presented at the 3rd workshop on Higher Luminosity B Factory, 6-7 August 2002, Kanagawa, Japan; Submitted to Phys. Rev.

    BKB\to K Transition Form Factor up to O(1/mb2){\cal O}(1/m^2_b) within the kTk_T Factorization Approach

    Full text link
    In the paper, we apply the kTk_T factorization approach to deal with the BKB\to K transition form factor F+,0BK(q2)F^{B\to K}_{+,0}(q^2) in the large recoil regions. The B-meson wave functions ΨB\Psi_B and ΨˉB\bar\Psi_B that include the three-particle Fock states' contributions are adopted to give a consistent PQCD analysis of the form factor up to O(1/mb2){\cal O} (1/m^2_b). It has been found that both the wave functions ΨB\Psi_B and ΨˉB\bar\Psi_B can give sizable contributions to the form factor and should be kept for a better understanding of the BB meson decays. Then the contributions from different twist structures of the kaon wavefunction are discussed, including the SUf(3)SU_f(3)-breaking effects. A sizable contribution from the twist-3 wave function Ψp\Psi_p is found, whose model dependence is discussed by taking two group of parameters that are determined by different distribution amplitude moments obtained in the literature. It is also shown that F+,0BK(0)=0.30±0.04F^{B\to K}_{+,0}(0)=0.30\pm0.04 and [F+,0BK(0)/F+,0Bπ(0)]=1.13±0.02[F^{B\to K}_{+,0}(0)/F^{B\to \pi}_{+,0}(0)]=1.13\pm0.02, which are more reasonable and consistent with the light-cone sum rule results in the large recoil regions.Comment: 22 pages and 6 figure

    Evading the CKM Hierarchy: Intrinsic Charm in B Decays

    Full text link
    We show that the presence of intrinsic charm in the hadrons' light-cone wave functions, even at a few percent level, provides new, competitive decay mechanisms for B decays which are nominally CKM-suppressed. For example, the weak decays of the B-meson to two-body exclusive states consisting of strange plus light hadrons, such as B\to\pi K, are expected to be dominated by penguin contributions since the tree-level b\to s u\bar u decay is CKM suppressed. However, higher Fock states in the B wave function containing charm quark pairs can mediate the decay via a CKM-favored b\to s c\bar c tree-level transition. Such intrinsic charm contributions can be phenomenologically significant. Since they mimic the amplitude structure of ``charming'' penguin contributions, charming penguins need not be penguins at all.Comment: 28 pages, 6 figures, published version. References added, minor change

    New Physics in CP Asymmetries and Rare B Decays

    Get PDF
    We review and update the effects of physics beyond the standard model on CP asymmetries in B decays. These asymmetries can be significantly altered if there are important new-physics contributions to \bqbqbar mixing. This same new physics will therefore also contribute to rare, flavor-changing B decays. Through a study of such decays, we show that it is possible to partially distinguish the different models of new physics.Comment: 42 pages, plain TeX (macros included), 1 figure (included). A few sentences added, references updated. Present manuscript is now identical to the version accepted for publication in Phys. Rev.

    Measurement of inclusive charged current interactions on carbon in a few-GeV neutrino beam

    Get PDF
    The SciBooNE Collaboration reports a measurement of inclusive charged current interactions of muon neutrinos on carbon with an average energy of 0.8 GeV using the Fermilab Booster Neutrino Beam. We compare our measurement with two neutrino interaction simulations: NEUT and NUANCE. The charged current interaction rates (product of flux and cross section) are extracted by fitting the muon kinematics, with a precision of 6-15% for the energy dependent and 3% for the energy integrated analyses. We also extract CC inclusive interaction cross sections from the observed rates, with a precision of 10-30% for the energy dependent and 8% for the energy integrated analyses. This is the first measurement of the CC inclusive cross section on carbon around 1 GeV. These results can be used to convert previous SciBooNE cross section ratio measurements to absolute cross section values.Comment: 21 pages, 16 figures. Accepted by Phys. Rev. D. Minor revisions to match the accepted versio
    corecore