Measurement of the form factors in the decay $D^+ \to \omega e^+ \nu_{e}$ and search for the decay $D^+ \to \phi e^+ \nu_{e}$

TL;DR

This paper reports precise measurements of the decay $D^+ o \omega e^+ u_{e}$, including form factor ratios, and sets an improved upper limit on the decay $D^+ o \phi e^+ u_{e}$, advancing understanding of charm semileptonic decays.

Contribution

First measurement of form factor ratios in $D^+ o \omega e^+ u_{e}$ decay and improved upper limit for $D^+ o \\phi e^+ u_{e}$ decay.

Findings

Branching fraction $\\mathcal{B}(D^+ o \\omega e^+ \\nu_{e})$ measured as $(1.63\pm0.11\pm0.08)\times 10^{-3}$.

Form factor ratios determined as $r_V=1.24\pm0.09\pm0.06$ and $r_2=1.06\pm0.15\pm0.05$.

Upper limit for $D^+ o \\phi e^+ \\nu_{e}$ decay set at $1.3 \times 10^{-5}$ at 90\% CL.

Abstract

Using 2.92 fb$^{-1}$ of electron-positron annihilation data collected at a center-of-mass energy of $\sqrt{s}= 3.773$ GeV with the BESIII detector, we present an improved measurement of the branching fraction $\mathcal{B}(D^+ \to \omega e^+ \nu_{e}) = (1.63\pm0.11\pm0.08)\times 10^{-3}$. The parameters defining the corresponding hadronic form factor ratios at zero momentum transfer are determined for the first time, we measure them to be $r_V = 1.24\pm0.09\pm0.06$ and $r_2 = 1.06\pm0.15 \pm 0.05$. The first and second uncertainties are statistical and systematic, respectively. We also search for the decay $D^+ \to \phi e^+ \nu_{e}$. An improved upper limit $\mathcal{B}(D^+ \to \phi e^+ \nu_{e}) < 1.3 \times 10^{-5}$ is set at 90\% confidence level.