Search for New Phenomena in Dijet Events using 13 TeV Proton-Proton Collision Data Collected With the ATLAS Detector

Dijet events are studied in the proton–proton collision dataset recorded at √s =13 TeV with the ATLAS detector at the Large Hadron Collider in 2015 and 2016, corresponding to an integrated luminosity of 37 fb−1. Invariant mass distributions are compared to background predictions and no significant deviation is observed. A new method for fitting the background component of the invariant mass distribution is employed. The dataset is used to set upper limits at a 95% confidence level on a range of new physics scenarios. Excited quarks with masses below 6.0 TeV are excluded, and limits are set on quantum black holes, heavy W’ bosons, W* bosons, and a range of masses and couplings in a Z’ dark matter mediator model. These results represent a substantial improvement over those obtained previously with lower integrated luminosity.