Measurement of the Hadronic Form Factors in Ds -> phi e nu Decays

TL;DR

This paper measures the hadronic form factors in the decay D_s+ to phi e+ nu_e, providing precise ratios and pole mass estimates that enhance understanding of semileptonic charm decays.

Contribution

It presents the first detailed measurement of the ratios of hadronic form factors and the axial pole mass in D_s+ to phi e+ nu_e decays using a four-dimensional rate analysis.

Findings

Measured form factor ratios r_V and r_2 with uncertainties.

Extracted the axial pole mass m_A with uncertainties.

Provided data consistent with theoretical models.

Abstract

Based on the measured four-dimensional rate for $D_{s}^+ to \phi e^+ \nu_e$ decays, we have determined the ratios of the three hadronic form factors, r_V=V(0)/A_1(0)= 1.636 \pm 0.067 \pm 0.038 and r_2=A_2(0)/A_1(0)= 0.705 \pm 0.056 \pm 0.029, using a simple pole ansatz for the $q^2$ dependence, with fixed values of the pole masses for both the vector and axial form factors. By a separate fit to the same data, we have also extracted the pole mass for the axial form factors, $m_A$: r_V=V(0)/A_1(0)= 1.633 \pm 0.081 \pm 0.068 ,r_2=A_2(0)/A_1(0)= 0.711 \pm 0.111 \pm 0.096 and m_A=(2.53^{+0.54}_{-0.35}\pm 0.54){{GeV/}c^2}