NLO corrections to lepton pair production beyond the Standard Model at hadron colliders

Abstract

We consider lepton pair production at a hadron collider in a class of effective theories with the relevant operators being four-fermion contact interaction. Despite the nonrenormalizable nature of the interaction, we explicitly demonstrate that calculating QCD corrections is both possible and meaningful. Calculating the corrections for various differential distributions, we show that these can be substantial and significantly different from those within the SM. Furthermore, the corrections have a very distinctive flavour dependence. And finally, the scale dependence of the cross sections are greatly reduced once the NLO corrections are taken into account.

Nonperturbative effect in threshold resummation

“…In Table 2 , we also compare the result of RES+NP calculation with a few other theory calculations which include the NLO [12,17,23], NNLO [24], NNLO-NLL [16], and the usual threshold resummation calculation (RES) [13]. .…”

QCD corrections to excited lepton (pair) production at the LHC

“…For this part of our calculation, we have followed the procedure of Ref. [22]. The physical hadronic cross section can be obtained by convoluting the finite coefficient functions with appropriate parton distribution functions and hence the inclusive differential cross section is given by 2S dσ…”

“…In this article, we aim to rectify this unsatisfactory state of affairs. While it may seem that the NLO corrections to the processes driven by such non-renormalizable interactions are ill-defined, it is not quite true [22,23]. In particular, if the interaction can be factorized into a current-current form, with colored fields appearing in only one current, then the NLO QCD corrections affect only this current and can be computed without any difficulties.…”

NNLO QCD corrections to the resonant sneutrino/slepton production at hadron colliders

“…In the next sections, we will elaborate on the sources of these uncertainties and provide systematic methods to reduce them. In [15], first results on the next-to-leading order (NLO) QCD corrections to sneutrino and charged slepton productions at hadron colliders were reported. These results were later confirmed and further NLO SUSY-QCD corrections were systematically incorporated in the analysis by the authors of [16].…”

“…Due to these reasons, we think that it is worthwhile to perform the next-next-to-leading order (NNLO) calculation to the aforementioned processes. In our previous paper [15], we used fixed R p coupling (λ ′ = 0.01) based on the assumption that its scale dependence is very weak, in addition the value of the coupling λ ′ was immaterial and only served to set an overall normalisation for the cross-section. In the present paper we have systematically included its scale dependence through the renormalisation group equations and we will discuss the impact of it in the next sections.…”