Gluino-squark production at the LHC: the threshold

An analysis of the cross section for hadronic production of gluino-squark pairs close to threshold is presented. Within the framework of non-relativistic QCD a significant enhancement compared to fixed order perturbation theory is observed which originates from the characteristic remnants of the gluino-squark resonances below the nominal pair threshold. The analysis includes all colour configurations of S-wave gluino-squark pairs, i.e. triplet, sextet and 1 5 representation. Matching coefficients at leading order are separately evaluated for all colour configurations. The dominant QCD corrections, arising from initial- and final-state radiation are included. The non-relativistic dynamics of the gluino pair is solved by calculating the Green's function in Next-to-Leading Order (NLO). The results are applied to benchmark scenarios, based on Snowmass Points and Slopes (SPS). As a consequence of the large decay rate of at least one of the constituents (squark or gluino), annihilation decays of the bound state ((g) over tilde(q) over tilde) -> gq, q gamma, qZ or q'W-+/- are irrelevant. Thus the signatures of gluino-quark production below and above the nominal threshold are identical. Numerical results for the cross section at the Large Hadron Collider (LHC) at root s = 7TeV and 14TeV are presented. The enhancement of the total cross section through final state interaction amounts to roughly 3%.