Search for electroweak-scale dijet resonances using trigger-level analysis with the ATLAS detector in $ 132\text{}\text{}{\mathrm{fb}}^{-1}$ of $ pp$ collisions at $ \sqrt{s}=13\text{}\text{}\mathrm{TeV}$

This article reports on a search for dijet resonances using $ 132\text{}\text{}{\mathrm{fb}}^{-1}$ of $ pp$ collision data recorded at $ \sqrt{s}=13\text{}\text{}\mathrm{TeV}$ by the ATLAS detector at the Large Hadron Collider. The search is performed solely on jets reconstructed within the ATLAS trigger to overcome bandwidth limitations imposed on conventional single-jet triggers, which would otherwise reject data from decays of sub-TeV dijet resonances. Collision events with two jets satisfying transverse momentum thresholds of $ {p}_{\mathrm{T}}\ge 85\text{}\text{}\mathrm{GeV}$ and jet rapidity separation of $ |{y}^{*}|<0.6$ are analysed for dijet resonances with invariant masses from 375 to $ 1800\text{}\text{}\mathrm{GeV}$. A data-driven background estimate is used to model the dijet mass distribution from multijet processes. No significant excess above the expected background is observed. Upper limits are set at 95% confidence level on coupling values for a benchmark leptophobic axial-vector $ {Z}^{\prime }$ model and on the production cross section for a new resonance contributing a Gaussian-distributed line-shape to the dijet mass distribution.