D+ to mu+nu and fD+ from 281 pb-1 at Psi(3770) from CLEO-c

TL;DR

This paper presents precise measurements of the D+ meson decay constant and branching fraction for D+ to mu+nu using data from the CLEO-c detector, providing insights into meson decay dynamics and constraints on new physics.

Contribution

First precise measurement of the D+ decay constant and branching fraction using CLEO-c data at Psi(3770), improving previous results and setting limits on non-Standard Model contributions.

Findings

Measured Br(D+ to mu+nu) = (4.40+-0.66+0.09-0.12) x 10^-4

Determined fD+ = (222.6+-16.7+2.8-3.4) MeV

Set 90% CL upper limit on Br(D+ to e+nu) < 2.4 x 10^-5

Abstract

We report improved measurements of branching fraction and decay constant fD+ in D+ to mu+nu using 281 pb-1 of data taken on the Psi(3770) resonance with the CLEO-c detector. We extract a relatively precise value for the decay constant of the D+ meson by measuring Br(D+ to mu+nu) = (4.40+-0.66+0.09-0.12)x10^-4 and find fD+ = (222.6+-16.7+2.8-3.4) MeV. We also set 90% confidence upper limit on Br(D+ to e+nu) < 2.4x10^-5 which limits contributions from non-Standard Model physics.