879 research outputs found

    Renormalization Group Equations for the CKM matrix

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    We derive the one loop renormalization group equations for the Cabibbo-Kobayashi-Maskawa matrix for the Standard Model, its two Higgs extension and the minimal supersymmetric extension in a novel way. The derived equations depend only on a subset of the model parameters of the renormalization group equations for the quark Yukawa couplings so the CKM matrix evolution cannot fully test the renormalization group evolution of the quark Yukawa couplings. From the derived equations we obtain the invariant of the renormalization group evolution for three models which is the angle α\alpha of the unitarity triangle. For the special case of the Standard Model and its extensions with v1v2v_{1}\approx v_{2} we demonstrate that also the shape of the unitarity triangle and the Buras-Wolfenstein parameters ρˉ=(11/2λ2)ρ\bar{\rho}=(1-{1/2}\lambda^{2})\rho and ηˉ=(11/2λ2)η\bar{\eta}=(1-{1/2}\lambda^{2})\eta are conserved. The invariance of the angles of the unitarity triangle means that it is not possible to find a model in which the CKM matrix might have a simple, special form at asymptotic energies.Comment: 9 page

    Investigating the trade-off between the effectiveness and efficiency of process modeling

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    Despite recent efforts to improve the quality of process models, we still observe a significant dissimilarity in quality between models. This paper focuses on the syntactic condition of process models, and how it is achieved. To this end, a dataset of 121 modeling sessions was investigated. By going through each of these sessions step by step, a separate ‘revision’ phase was identified for 81 of them. Next, by cutting the modeling process off at the start of the revision phase, a partial process model was exported for these modeling sessions. Finally, each partial model was compared with its corresponding final model, in terms of time, effort, and the number of syntactic errors made or solved, in search for a possible trade-off between the effectiveness and efficiency of process modeling. Based on the findings, we give a provisional explanation for the difference in syntactic quality of process models
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