Sensitivity projections for a search for new phenomena at high dilepton mass for the LHC Run 3 and the HL-LHC

A projection of the sensitivity for a search for new physics in proton-proton collisions with two energetic leptons, e or $\mu$, in the final state is presented. Two datasets are considered: a combination of the Run 2 dataset with the expected Run 3 dataset, $140\,\mathrm{fb}^{-1}$ at a center-of-mass energy $\sqrt{s} = 13\,\mathrm{TeV}$ and $160\,\mathrm{fb}^{-1}$ at $\sqrt{s} = 13.6\,\mathrm{TeV}$ respectively, as well as the dataset expected from the high-luminosity LHC (HL-LHC) corresponding to $3000\,\mathrm{fb}^{-1}$ at $\sqrt{s} = 14\,\mathrm{TeV}$. With these datasets, significant improvement in the sensitivity of searches for new physics will be achieved. In the search for new heavy gauge bosons $\mathrm{Z}^{\prime}$, the expected exclusion limit at $95\%$ CL will be improved by about 300$\,\mathrm{GeV}$ with the combination of the Run 2 and Run 3 datasets, and by about $1.7\,\mathrm{TeV}$ with the HL-LHC dataset. The $5\,\sigma$ discovery potential for these particles is also assessed. Additionally, the expected sensitivity for testing lepton flavor universality by measuring the dimuon-to-dielectron ratio at high mass with these two datasets is presented.