Designing a search for QCD Instantons with the ATLAS detector

A search of QCD Instanton induced processes was designed using Monte-Carlo generated signal and background samples in this project. The properties of Instanton induced processes, such as producing a large number of particles spherically, were used to separate the signals from the background processes. Cuts were developed by comparing the distribution of observables in the signal and background processes in the reconstructed mass range of 30 GeV to 60 GeV. 80.0% efficiency of correctly identifying the signal events and 89.6% for the background events were achieved by applying cuts on five observables: number of tracks, transverse mass, standard deviation of pseudorapidity, sum of inverse of transverse momentum and sphericity.