Semileptonic D-decays and Lattice QCD

TL;DR

This paper investigates four lattice QCD strategies to extract D-meson semileptonic decay form factors, identifying two that significantly reduce systematic uncertainties, thereby improving the precision of CKM matrix element determinations.

Contribution

The study introduces and tests four methods for calculating D-decay form factors, highlighting two that effectively lower systematic errors in lattice QCD computations.

Findings

Double ratio strategies reduce systematic uncertainties

Two methods significantly improve form factor accuracy

Enhances precision in CKM matrix element extraction

Abstract

We explore four different strategies to extract the D-meson semileptonic decay form factors from the Green functions computed in QCD numerically on the lattice. From our numerical tests we find that two such strategies, based on the use of double ratios of 3-point correlation functions, lead to an appreciable reduction of systematic uncertainties. This is an important step in reducing the overall uncertainty in the lattice QCD results for the D-decay form factors which are needed to determine the CKM entries |Vcd| and |Vcs| experimentally, that are nowadays known by imposing the unitarity of the CKM matrix.