Measurements of the qsq dependence of the D0 to K mu nu and D0 to pi mu nu form factors

TL;DR

This paper presents new measurements of the q^2 dependence of the D0 to K mu nu and pi mu nu form factors using Fermilab data, comparing results to lattice QCD predictions and parameterizations.

Contribution

It provides the first detailed q^2 dependence measurements of these form factors and compares them to theoretical models, improving understanding of semileptonic D meson decays.

Findings

Measured pole masses: 1.93 GeV/c^2 for D0 to K mu nu and 1.91 GeV/c^2 for D0 to pi mu nu.

Determined the ratio f-^{K}(0)/f+^{K}(0) = -1.7 with large uncertainties.

Compared form factors to lattice QCD and pole dominance models.

Abstract

Using a large sample of D0 to K mu nu and pi mu nu decays collected by the FOCUS photoproduction experiment at Fermilab, we present new measurements of the q^2 dependence for the f+(q^2) form factor. These measured f+(q^2) form factors are fit to common parameterizations such as the pole dominance form and compared to recent unquenched Lattice QCD calculations. We find m_pole = 1.93+-0.05+-0.03 GeV/c^2 for D0 to K mu nu and m_pole = 1.91+0.30-0.15+-0.07 GeV/c^2 for D0 to pi mu nu and f-^{K}(0)/f+^{K}(0) = -1.7+1.5-1.4+-0.3.