Nonleptonic Two Body Decays of Charmed Mesons

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Nonleptonic Two Body Decays of Charmed Mesons. By YU Fusheng ( ) 2011 Cross Strait Meeting on Particle Physics and Cosmology. Outline. Introduction phenomenology heavy flavor physics Generalized Factorization Approach Pole Dominance Model Summary. Topological diagrams. - PowerPoint PPT Presentation


<ul><li><p>By YU Fusheng ()</p><p>2011 Cross Strait Meeting on Particle Physics and Cosmology</p><p>*</p></li><li><p>Introduction phenomenology heavy flavor physicsGeneralized Factorization ApproachPole Dominance Model Summary*</p></li><li><p>*</p></li><li><p>Effective Hamiltonian: basic tool to study the hadronic decay of heavy flavor mesons are Wilson coefficients and are four quark operators:</p><p>*</p></li><li><p>The amplitude of is</p><p>The key is to tackle :</p><p>Nave factorizationGeneralized FactorizationPole dominance modelQCD factorization (QCDF)Perturbative QCD approach (PQCD)Soft-collinear effective theory (SCET)*</p></li><li><p>Assumption: the matrix element is factorized into two parts,</p><p>Neglect the annihilation and nonfactorization contributions*</p></li><li><p> for color-favored (T) and color-suppressed (C) processes. are universal and process independent.</p><p>Difficulties: are renormalization scale and scheme dependentfail to describe the color-suppressed decay modes due to the smallness of </p><p>*</p></li><li><p>Consider non-factorization contributions </p><p>In the large-Nc approach,</p><p>A large relative strong phase between diagrams is induced by final-state interactions*</p></li><li><p>Annihilation diagrams are neglected as an approximation in the factorization model. </p><p>We will calculate considerable resonant effects of annihilation diagrams in a single pole dominance model.*</p></li><li><p>Only consider the lowest lying polesExample: *</p></li><li><p>The weak matrix element is evaluated in the vacuum insertion approximation,</p><p>The effective strong coupling </p><p>Inserting the propagator of intermediate state, the decay amplitude is*</p></li><li><p>Annihilation Emission diagrams</p><p>Pole Model Generalized Factorization Approach</p><p>Consider relative strong phases between topological diagrams</p><p>Calculate the branching ratios of and *</p></li><li><p>*</p></li><li><p>*</p></li><li><p>*</p></li><li><p>*</p></li><li><p>*</p></li><li><p>*</p></li><li><p>*</p></li><li><p> , large annihilation type contributions agree with the experiment data better than that of the diagrammatic approach.*</p></li><li><p>*</p></li><li><p>Large annihilation type contributions agree with the experiment data.</p><p>The single pole resonance effect dominates the annihilation type contribution in most decay modes. </p><p>*</p></li><li><p>Small annihilation contributions in this modelDue to the smallness of decay constants of intermediate scalar mesons.</p><p>*</p></li><li><p> and are studied on the basisGeneralized factorization for emission diagramsPole model for resonance effect of annihilation diagramsRelative strong phases between topological diagrams</p><p>Our results agree with experimental data</p><p>Annihilation contributions in pole model small to , but large to *</p></li><li><p>*</p></li><li><p>*</p></li><li><p>*</p></li><li><p>*</p></li><li><p>The amplitudes satisfy the isospin triangle relation but</p><p>Besides, importance of inelastic final state interactions of D meson decays in which on-shell intermediate states will contribute imaginary parts.*</p></li><li><p>*</p><p>*</p></li></ul>