Simultaneous least-squares treatment of statistical and systematic uncertainties

We present a least-squares method for estimating parameters from measurements of event yields in the presence of background and crossfeed. We adopt a unified approach to incorporating the statistical and systematic uncertainties on the experimental measurements input to the fit. We demonstrate this method with a fit for absolute hadronic D   meson branching fractions, measured in e+e-→ψ(3770)→DD¯ transitions.