light would enhance the rate of production of final states with leptons in collider experiments [@Belanger:2012jn; @Arganda:2018hdn].

In this analysis, we study the simplified model [@Alwall:2008ag; @Alwall:2008va; @Alves:2011wf] of direct pair production shown in Fig. \[fig:diagram\]. We assume that the decays to a lepton and , the lightest neutralino, which is the LSP in this model. The search is challenging because of the extremely small production cross section expected for this signal, as well as the large backgrounds. The most sensitive previous searches for direct pair production were performed at the CERN LEP collider [@Heister:2001nk; @Abdallah:2003xe; @Achard:2003ge; @Abbiendi:2003ji], excluding masses at 95% confidence level () up to $\approx$90for neutralino masses up to 80in some models. At the LHC, the ATLAS [@Aad:2014yka; @Aad:2015eda] and CMS [@SUS14022] Collaborations have also performed searches for direct pair production using 8data, and the CMS Collaboration has reported a search for direct pair production in an initial sample of 35.9at 13collected in 2016 [@Sirunyan:2018vig]. This paper presents a significant improvement in search sensitivity, which was limited by the small signal production rates, through the incorporation of improved analysis techniques and the inclusion of the data collected in 2017. The data used correspond to a total integrated 