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Gauge-Independent W-Boson Partial Decay Widths

B. A. Kniehl·F. Madricardo·M. Steinhauser
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Abstract

We calculate the partial decay widths of the W boson at one loop in the standard model using the on-shell renormalization scheme endowed with a gauge-independent definition of the Cabibbo-Kobayashi-Maskawa (CKM) mixing matrix. We work in $R_ξ$ gauge and explicitly verify that the final expressions are independent of the gauge parameters. Furthermore, we establish the relationship between the on-shell and $\bar{\mathrm{MS}}$ definitions of the CKM matrix, both in its generic form and in the Wolfenstein parameterization. As a by-product of our analysis, we recover the beta function of the CKM matrix.

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B. A. Kniehl, F. Madricardo, M. Steinhauser. 2000-07-13. Gauge-Independent W-Boson Partial Decay Widths. https://doi.org/10.1103/physrevd.62.073010

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