Enhancement of charm signal significance in hadroproduction

Given several sets of candidate charm decay events, where some candidates are true decays but most are random background coincidences, it is shown that signal significance can be maximized by assigning to the candidates in each set a weight equal to the ratio of signal to variance in that set. This method improves on the traditional analysis which assigns unit weight to selected candidate events and zero weight to the others. When the sets are defined along a range of some parameter the assigned weights constitute a smooth function of the value of the parameter. The technique is generalized to a multiplicity of parameters, and the utility of the method is demonstrated by application to the charmed meson decay D0 → K−π+ (plus charge conjugate) signal in Fermilab Experiment E769.