Measurement of the branching ratio of the decay D^0 -> \pi^-\mu^+\nu relative to D^0 -> K^-\mu^+\nu

TL;DR

This paper reports a new measurement of the ratio of branching fractions for two D^0 meson decays involving muons, providing insights into charm quark transitions and form factors.

Contribution

It provides the first precise measurement of the branching ratio of D^0 -> π^-μ^+ν relative to D^0 -> K^-μ^+ν and an improved determination of the form factor ratio.

Findings

Branching ratio of D^0 -> π^-μ^+ν is 0.074 ± 0.008 ± 0.007.

Form factor ratio |f_+^{π}(0)/f_+^{K}(0)| is 0.85 ± 0.04 ± 0.04 ± 0.01.

Results improve understanding of charm semileptonic decays.

Abstract

We present a new measurement of the branching ratio of the Cabibbo suppressed decay D^0\to \pi^-\mu^+\nu relative to the Cabibbo favored decay D^0\to K^-\mu^+\nu and an improved measurement of the ratio |\frac{f_+^{\pi}(0)}{f_+^{K}(0)}|. Our results are 0.074 \pm 0.008 \pm 0.007 for the branching ratio and 0.85 \pm 0.04 \pm 0.04 \pm 0.01 for the form factor ratio, respectively.