New Measurements of the Ds to Phi mu nu Form Factor Ratios

TL;DR

This paper reports new measurements of semileptonic form factor ratios rV and r2 in Ds to Phi mu nu decays, providing data that aligns with previous measurements in similar processes, enhancing understanding of charm meson decays.

Contribution

First precise measurement of the form factor ratios rV and r2 in Ds to Phi mu nu decays using Fermilab data, expanding knowledge of charm semileptonic decay dynamics.

Findings

Measured rV = 1.549 ± 0.250 ± 0.145

Measured r2 = 0.713 ± 0.202 ± 0.266

Results are consistent with D+ to K*bar mu nu measurements

Abstract

Using a large sample of Ds to Phi mu nu decays collected by the FOCUS photoproduction experiment at Fermilab, we present new measurements of two semileptonic form factor ratios: rV and r2. We find rV = 1.549 \pm 0.250 \pm 0.145 and r2 = 0.713 \pm 0.202 \pm 0.266. These values are consistent with the rV and r2 form factors measured for the process D+ to K*bar mu nu.