# Measurement of the Hadronic Form Factor in D0 --> K- e+ nue Decays

## TL;DR

This study measures the shape of the hadronic form factor in D0 decays to K- e+ nue using a large data sample, providing model-independent results and comparing with theoretical predictions.

## Contribution

It presents a model-independent measurement of the hadronic form factor f+(q2) in D0 --> K- e+ nue decays and determines its normalization at q2=0.

## Key findings

- Measured the form factor shape in a model-independent way
- Determined the decay branching fraction ratio RD
- Calculated the form factor normalization f+(0) with uncertainties

## Abstract

The shape of the hadronic form factor f+(q2) in the decay D0 --> K- e+ nue has been measured in a model independent analysis and compared with theoretical calculations. We use 75 fb(-1) of data recorded by the BABAR detector at the PEPII electron-positron collider. The corresponding decay branching fraction, relative to the decay D0 --> K- pi+, has also been measured to be RD = BR(D0 --> K- e+ nue)/BR(D0 --> K- pi+) = 0.927 +/- 0.007 +/- 0.012. From these results, and using the present world average value for BR(D0 --> K- pi+), the normalization of the form factor at q2=0 is determined to be f+(0)=0.727 +/- 0.007 +/- 0.005 +/- 0.007 where the uncertainties are statistical, systematic, and from external inputs, respectively.