Squark anti-squark pair production at the LHC: the electroweak contribution
Wolfgang Hollik, Edoardo Mirabella
TL;DR
The paper computes the complete next-to-leading order electroweak corrections of O(αs^2 α) to diagonal squark–anti-squark production at the LHC within the MSSM, incorporating virtual EW loops, real photon and gluon bremsstrahlung, and photon–gluon initiated processes. It systematically treats IR and collinear singularities across multiple partonic channels and renormalizes the squark sector in an on-shell scheme. Numerical analyses across four SUSY benchmark scenarios show that electroweak effects can reach 20–25% of the cross section, especially for left-handed squarks, with the gluon-fusion and qq̄ channels contributing differently as squark masses vary. The results emphasize the necessity of including NLO EW corrections for precision predictions and suggest NNLO QCD could be comparably important for full accuracy.
Abstract
We present the complete NLO electroweak contribution of $\mathcal{O}(α^2_s α)$ to the production of diagonal squark--anti-squark pairs in proton--proton collisions. Compared to the lowest-order $\mathcal{O}(α_sα+ α^2)$ electroweak terms, the NLO contributions are also significant. We discuss the LO and NLO electroweak effects in cross sections and distributions at the LHC for the production of squarks different from top squarks, in various supersymmetric benchmark scenarios.