Precision Measurement of B(D+ -> mu+ nu) and the Pseudoscalar Decay Constant fD+
Abstract
We measure the branching ratio of the purely leptonic decay of the D+ meson with unprecedented precision as B(D+ -> mu+ nu) = (3.82 +/- 0.32 +/- 0.09)x10^(-4), using 818/pb of data taken on the psi(3770) resonance with the CLEO-c detector at the CESR collider. We use this determination to derive a value for the pseudoscalar decay constant fD+, combining with measurements of the D+ lifetime and assuming |Vcd| = |Vus|. We find fD+ = (205.8 +/- 8.5 +/- 2.5) MeV. The decay rate asymmetry [B(D+ -> mu+ nu)-B(D- -> mu- nu)]/[B(D+ -> mu+ nu)+B(D- -> mu- nu)] = 0.08 +/- 0.08, consistent with no CP violation. We also set 90% confidence level upper limits on B(D+ -> tau+ nu) < 1.2x10^(-3) and B(D+ -> e+ nu) < 8.8x10^(-6).
Cite
@article{arxiv.0806.2112,
title = {Precision Measurement of B(D+ -> mu+ nu) and the Pseudoscalar Decay Constant fD+},
author = {CLEO Collaboration and B. I. Eisenstein},
journal= {arXiv preprint arXiv:0806.2112},
year = {2010}
}
Comments
24 pages, 11 figures and 6 tables, v2 replaced some figure vertical axis scales, v3 corrections from PRD review