Hadronic production of top-squark pairs with electroweak NLO contributions

TL;DR

This work delivers the complete electroweak next-to-leading-order corrections to hadronic top-squark pair production in the MSSM, including interference with QCD and photon-induced production channels enabled by a nonzero proton photon density. The authors implement a full set of virtual and real EW contributions, carefully handling soft and collinear singularities with phase-space slicing and PDF factorization, and incorporate the photon-induced $g\gamma$ channel at NLO QED. Numerical results across multiple SPS scenarios show that EW NLO effects can reach 10–20% in high-$p_T$ and high-$M_{inv}$ regions and can be comparable to or larger than other corrections, emphasizing the importance of these contributions for precise stop searches and MSSM constraints. The analysis demonstrates that photon-induced processes are non-negligible and that interference terms are essential for a consistent, IR-finite prediction of stop-pair production at the LHC.

Abstract

Presented are complete next-to-leading order electroweak (NLO EW) corrections to top-squark pair production at the Large Hadron Collider (LHC) within the Minimal Supersymmetric Standard Model (MSSM). At this order, also effects from the interference of EW and QCD contributions have to be taken into account. Moreover, photon-induced top-squark production is considered as an additional partonic channel, which arises from the non-zero photon density in the proton.