UC Irvine

In this thesis a few approaches are explored to advance resonance finding searches in collider physics. Two analyses in the dimuon and dijet initial-state radiation(ISR)final state resonance are searched using proton-proton collisions at √s=13 TeV with an integrated luminosity of 139/fb, collected by the ATLAS experiment. No statistically significant excess is seen in the dijetISR search. In the dimuon search, a novel background estimation method is developed, in which the smooth but unknown background is estimated using a Gaussian process fit.