Spatial correlations applied to gamma/hadron discrimination in the ARGO-YBJ experiment

Following recently proposed approaches on gamma/hadron separation, spatial correlations among secondary charged particles in extensive air showers have been studied for the case of the ARGO-YBJ experiment, which represents a particularly suited detector in this respect because of its “continuous-carpet” geometry. Two different types of statistics have been considered, namely the nearest-neighbor spacing distribution (NNSD) and the variance of the number of secondary particles at given distance. The results of this preliminary investigation are reported.