Combining subjet algorithms to enhance ZH detection at the LHC

Abstract

The signal for a highly boosted heavy resonance competing against a background of light parton jets at the LHC can be enhanced by analyzing subjets in the "fat" jet that possibly contains the heavy resonance. Three methods for doing this are known as filtering, pruning, and trimming. We study the possibility of combining these methods using a relative likelihood approach. We find that, because the methods are not the same, one achieves an enhanced statistical power by combining them. We illustrate the possibilities first with a simple problem of combining trimming and pruning to enhance the signal for finding a boosted top quark. We then study the more difficult problem of disentangling from the background the signal for the production of a Higgs boson in association with a Z-boson. For this problem, we combine filtering, trimming, and pruning.