Background ionization behavior and composition for combined ionization energy and disappearing track analysis in the ATLAS detector

The Standard Model of particle physics describes the matter that we interact with on a daily basis, as well as three of the four fundamental forces that mediate interactions between them. Despite the Standard Model's accuracy, theoretical considerations as well as numerous lines of experimental evidence indicate that it is incomplete. In the search for long-lived charginos as part of a supersymmetric extension to the standard model, we are searching for a distinct signature of anomalous ionization energy with a disappearing track signature as a part of the ATLAS Experiment at the Large Hadron Collider. To support of this, we are looking to characterize the ionization behavior of both background and signal, as well as seeking to understand the effect of potential discriminants against background on simulated signal and background. In this talk, we will present a study on the composition and behavior of background in the search for long-lived charginos, as well as summarize which selections will best bias against background in favor of signal.