Kinematic reconstruction of the charged Higgs boson mass in the H⁺ → tb̅ process using a likelihood technique

Abstract

An extension of the Standard Model of particle physics is the introduction of two Higgs doublets to break electroweak symmetry instead of a single Higgs boson. This results in a couple of Higgs bosons, including a charged scalar, H^±. The H⁺ is produced as a mediator in a scattering process of a top quark and a bottom quark from two gluons. This research is focused on how to reconstruct the mass of the H⁺ boson using a novel statistical method based on weighting every single possible combination of the final state products corresponding to a weighted average mass per event. Histograms of the invariant mass of the H⁺ are produced using simulated datasets with different H⁺ truth mass. It is found that low truth masses produces histograms with higher peaks, which gradually flattens as the truth mass is increased. A separation between signal and background events can be distinguished at higher truth mass at the cost of having a flatter distribution for the signal events. This research was done using simulated data from the ATLAS experiment.