Improved Measurement of the Pseudoscalar Decay Constant $f_{D_{s}}$

TL;DR

This paper reports a new measurement of the Ds meson decay constant, f_{Ds}, using data from the CLEO II detector, providing a more precise value that is compared with theoretical models.

Contribution

The paper introduces a new experimental determination of f_{Ds} based on a ratio of decay widths, improving the precision of previous measurements.

Findings

Measured f_{Ds} = (280 +/- 17 +/- 25 +/- 34) MeV

Derived from a ratio of decay widths and branching ratios

Results compared with theoretical model predictions

Abstract

We present a new determination of the Ds decay constant, f_{Ds} using 5 million continuum charm events obtained with the CLEO II detector. Our value is derived from our new measured ratio of widths for Ds -> mu nu/Ds -> phi pi of 0.173+/- 0.021 +/- 0.031. Taking the branching ratio for Ds -> phi pi as (3.6 +/- 0.9)% from the PDG, we extract f_{Ds} = (280 +/- 17 +/- 25 +/- 34){MeV}. We compare this result with various model calculations.