Search for D to phi l nu and measurement of the branching fraction for D to phi pi

TL;DR

This paper reports measurements and upper limits for various D+ meson decays involving phi mesons, using BESII data, providing new insights into charm meson decay branching fractions.

Contribution

First measurement of the branching fraction for D+ to phi pi+ and upper limits for semileptonic D+ decays involving phi, using BESII data at 3.773 GeV.

Findings

Upper limits for BF(D+ to phi e+ nu_e) and BF(D+ to phi mu+ nu_mu) are set at 2.01% and 2.04%.

The ratio of BF(D+ to phi pi+) to BF(D+ to K- pi+ pi+) is measured as 0.057 ± 0.011 ± 0.003.

The branching fraction for D+ to phi pi+ is measured as (5.2 ± 1.0 ± 0.4) x 10^-3.

Abstract

Using a data sample of integrated luminosity of about 33 pb$^{-1}$ collected around 3.773 GeV with the BESII detector at the BEPC collider, the semileptonic decays $D^+ \to \phi e ^+\nu_e$, $D^+ \to \phi \mu^+\nu_\mu$ and the hadronic decay $D^+ \to \phi \pi^+$ are studied. The upper limits of the branching fractions are set to be $BF(D^+ \to \phi e ^+\nu_e) <$ 2.01% and $BF(D^+ \to \phi \mu^+ \nu_\mu) <$ 2.04% at the 90% confidence level. The ratio of the branching fractions for $D^+ \to \phi \pi^+$ relative to $D^+ \to K^-\pi^+\pi^+$ is measured to be $0.057 \pm 0.011 \pm 0.003$. In addition, the branching fraction for $D^+ \to \phi \pi^+$ is obtained to be $(5.2 \pm 1.0 \pm 0.4) \times 10^{-3}$.