Quark mixing renormalization effects in the determination of |V_{tq}|

TL;DR

This paper investigates how different renormalization schemes affect the measurement of CKM matrix elements from top-quark decay widths, highlighting the importance of scheme choice in precision determinations.

Contribution

It provides a numerical analysis of renormalization scheme effects on CKM parameters derived from top decay data, without assuming unitarity.

Findings

Renormalization schemes cause measurable shifts in |V_{tq}|^2 values.

Scheme choice impacts the extraction of |V_{tb}|^2 from decay ratios.

Results inform more accurate top-quark decay analyses.

Abstract

We study the numerical effects of several renormalization schemes of the Cabibbo-Kobayashi-Maskawa (CKM) quark mixing matrix on the top-quark decay widths. We then employ these results to infer the relative shifts in the CKM parameters |V_{tq}|^2 due to the quark mixing renormalization corrections, assuming that they are determined directly from the top-quark partial decay widths, without imposing unitarity constraints. We also discuss the implications of these effects on the ratio R = Gamma(t -> Wb) / Gamma_t and the determination of |V_{tb}|^2.