Working group 1 summary: $V_{ud}$, $V_{us}$, $V_{cd}$, $V_{cs}$ and semileptonic/leptonic $D$ decays

TL;DR

This paper summarizes the discussions and findings of Working Group 1 at the 12th CKM Unitarity Triangle Workshop, focusing on the determination of CKM matrix elements $V_{ud}$, $V_{us}$, $V_{cd}$, $V_{cs}$, and related semileptonic and leptonic $D$ decays.

Contribution

It provides an overview of current experimental and theoretical progress in measuring CKM matrix elements and $D$ decay processes, highlighting recent advancements and challenges.

Findings

Updated values of CKM matrix elements with improved precision

Assessment of first-row unitarity of the CKM matrix

Summary of experimental and theoretical uncertainties in $D$ decays

Abstract

We summarize the program of working group 1 at the 12th Workshop on the CKM Unitarity Triangle, whose main subjects covered $V_{ud}$, $V_{us}$, and first-row unitarity as well as $V_{cd}$, $V_{cs}$, and (semi-)leptonic $D$ decays.