UC Irvine

A search for new physics resonances in the dijet invariant mass spectrum is presented here. Dijet events are collected at center of mass energy of 13 TeV with the ATLAS detector at the Large Hadron Collider in 2015 and 2016, equating to a total integrated luminosity of 37 $fb^{-1}$. This data is compared to background predictions, and no significant deviations from the expected is seen. Therefore, the dataset is used to set improved upper limits on the mass of four benchmark signal models and one generic model at 95\% CL. These limits exclude excited quarks with masses below 6.0 TeV, quantum black holes below 8.9 TeV, heavy W' boson masses below 3.6 TeV, and $W^{*}$ bosons masses below 3.4 TeV and between 3.77-3.85 TeV; as well as limits on a range of masses and couplings in a $Z'$ dark matter mediator model. Model-independent limits are also set on signals with a Gaussian shape at various mass resolutions. Finally, a proof of concept study is done on a new method to predict dijet backgrounds, which may be implemented in future analyses.