Shower deconstruction is a method to look for new physics in a hadronic environment. It is the first approach of an all-order resummed matrix element method.
By calculating the likelihood if a fatjet looks more like signal or more like background
it allows to perform an hypothesis test. By specifying where to cut on chi, you can purify your sample and reject QCD backgrounds.
You can download the source code here . It includes a README file and an example code that explains how you can use shower deconstruction in your analysis.