759 research outputs found

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

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    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

    New Physics and CP Angles Measurement at B Factory

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    We have analyzed how much the CPCP angles to be measured at B factories can deviate from the geometrical ones defined in unitarity triangle under the existence of new physics. The measurements are given in rephasing invariant form. If KM matrix is not a 3×33\times 3 and unitary matrix, ϕ~1\tilde\phi_1 and ϕ~3\tilde\phi_3 is affected, and the value of ϕ~3\tilde\phi_3 depends on the decay mode. The deviation is constrained to be less than the experimental precision attained in the next decade by the available data of the magnitude of KM matrix elements. Deviation of the sum of three angles from π\pi cannot be detected unless new physics contributes significantly to bb decay or DD meson system.Comment: 11 pages, 1 figure in eps format, LaTeX, epsfig.st

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

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    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

    Study of color suppressed modes B0Dˉ()0η()B^0 \to \bar D^{(*)0} \eta^{(\prime)}

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    The color suppressed modes B0Dˉ()0η()B^0 \to \bar D^{(*)0} \eta^{(\prime)} are analyzed in perturbative QCD approach. We find that the dominant contribution is from the non-factorizable diagrams. The branching ratios calculated in our approach for B0Dˉ()0ηB^0 \to \bar D^{(*)0} \eta agree with current experiments. By neglecting the gluonic contribution, we predict the branching ratios of B0Dˉ()0ηB^0 \to \bar D^{(*)0} \eta' are at the comparable size of B0Dˉ()0π0B^0 \to \bar D^{(*)0} \pi^0, but smaller than that of B0Dˉ()0ηB^0 \to \bar D^{(*)0} \eta .Comment: revtex, 5 pages, axodraw.st

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

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    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

    Moderate Supersymmetric CP Violation

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    It is well known that supersymmetry (SUSY) gives neutron and electron electric dipole moments (dnd_n and ded_e) which are too large by about 10310^{3}. If we assume a SUSY model cannot contain fine-tunings or large mass scales, then one must require that the SUSY breaking mechanism give real soft breaking parameters, in which case the minimal SUSY model has no CPCP violation other than from the CKM matrix (besides possible strong CPCP violating effects). We show that in non-minimal SUSY models, a moderate amount of CPCP violation can be induced through one loop corrections to the scalar potential, giving an effective phase of order 10310^{-3}, and thus implying dnd_n and ded_e can be near their current experimental bounds naturallynaturally. This moderate amount of SUSY CPCP violation could also prove important for models of electroweak baryogenesis. We illustrate our results with a specific model.Comment: 19pp plain LATEX, 1 fig (by EMAIL request), TRI-PP-93-86. (Some clarifying comments about renormalizability added--version to appear in Phys. Rev. D

    Factorization and Endpoint Singularities in Heavy-to-Light decays

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    We prove a factorization theorem for heavy-to-light form factors. Our result differs in several important ways from previous proposals. A proper separation of scales gives hard kernels that are free of endpoint singularities. A general procedure is described for including soft effects usually associated with the tail of wavefunctions in hard exclusive processes. We give an operator formulation of these soft effects using the soft-collinear effective theory, and show that they appear at the same order in the power counting as the hard spectator contribution.Comment: 5 pages, Added details on comparison with the literatur
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