Bi-Event Subtraction Technique at Hadron Colliders

TL;DR

The paper introduces the Bi-Event Subtraction Technique (BEST), a method to model and subtract combinatoric backgrounds in particle decay reconstruction at hadron colliders, demonstrated through simulations of top quark and supersymmetric decay chains.

Contribution

It generalizes the BEST method by applying it iteratively to fully reconstruct complex cascade decays at hadron colliders.

Findings

Effective background reduction demonstrated in simulations

Successful reconstruction of top quark decay chain

Potential application to supersymmetric decay chains

Abstract

We propose the Bi-Event Subtraction Technique (BEST) as a method of modeling and subtracting large portions of the combinatoric background during reconstruction of particle decay chains at hadron colliders. The combinatoric background arises when it is impossible to know experimentally which observed particles come from the decay chain of interest. The background shape can be modeled by combining observed particles from different collision events and be subtracted away, greatly reducing the overall background. This idea has been demonstrated in various experiments in the past. We generalize it by showing how to apply BEST multiple times in a row to fully reconstruct a cascade decay. We show the power of BEST with two simulated examples of its application towards reconstruction of the top quark and a supersymmetric decay chain at the Large Hadron Collider.