2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/229639We explore the opportunity to look for quark compositeness in the early stages of the LHC running by analyzing high-$E_T$ dijet production. The quark substructure that will manifest itself by affecting various kinematic distributions at the center-of-mass energy $E_{CM}$=10 TeV and in the integrated luminosity range from 0.5 to 10 fb$^{-1}$ is investigated. The estimation of the characteristic energy scale $Λ$, based on the novel, potentially powerful observable, is found to be sensitive to the sign of the interference between Standard Model and four-fermion contact interactions. We find the lower limits on $Λ$ at the LHC to be about 10.5(15.0) TeV for constructive interference and 8.5(11.5) TeV for destructive one at the integrated luminosity 0.5(10) fb$^{-1}$ and $E_{CM}=10$ TeV.9 pagesHigh Energy Physics - PhenomenologyLHC Probe of Quark Substructure at the Early Stages of Runningtext