This study is the result of my work during my master thesis and my very first paper, for which I am also the first-author. I studied the sensitivity of Tevatron dijet measurements to heavy new‐physics effects parameterized by four‐quark operators in the Standard Model Effective Field Theory (SMEFT). Focusing on the Warsaw‐basis dimension‑six contact interactions, I calculated their interference with the QCD amplitude in dijet production as a function of the invariant mass and rapidity of the two leading jets. I enforced a consistent truncation of the SMEFT expansion at order 1/Λ² and supplemented our signal prediction with a mathematical consistent theoretical uncertainty estimate accounting for neglected 1/Λ⁴ effects from both squared dimension‑six and unknown dimension‑eight terms.
Recasting the D0 measurement of the dijet mass spectrum with \(\eta\) max up to 2.4 using 0.7 fb⁻¹ of data, we generated signal templates in MadGraph5 and applied the same kinematic selections and NLO background as the experiment. After combining statistical, systematic, and theoretical errors, we found that no meaningful bound on the Wilson coefficients can be derived from these data. We then projected the potential reach of a full 10 fb⁻¹ dataset under optimistic and conservative assumptions about systematic‐error scaling and again saw no sensitivity to new contact interactions. Our results demonstrate the general difficulty of obtaining model‐independent SMEFT constraints from relatively low‐luminosity, systematics‑limited hadron‐collider measurements. We conclude that Tevatron dijet data alone cannot probe four‑quark contact operators at the cutoff scales of interest, underscoring the need for higher‑precision or higher‑energy observables—such as those from the LHC—to place reliable EFT bounds.
Read the full JHEP article here.