Precision Measurement of B(D+ -> mu+ nu) and the Pseudoscalar Decay Constant fD+

Preprint

14 July 2008

preprint
Published by arXiv in arXiv

https://doi.org/10.48550/arXiv.0806.2112

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).

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All Related Versions

Version 1, 2008-06-12, ArXiv
Version 2, 2008-06-14, ArXiv
Version 3, 2008-07-14, ArXiv
Published version: Physical Review D, 78 (5), 052003.

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