Doubly charged scalar at the High-Luminosity and High-Energy LHC

Doubly charged scalars are common figures in several beyond the Standard Model studies, especially those related to neutrino masses. In this work, we estimate the High-Luminosity (HL-LHC) and High-Energy LHC (HE-LHC) sensitivity to doubly charged scalars assuming that they decay promptly and exclusively into charged leptons. Our study focuses on the fit to the same-sign dilepton mass spectra and it is based on proton-proton collisions at 13 TeV, 14 TeV and 27 TeV with integrated luminosity of L = 139 fb(-1), 3 ab(-1) and 15 ab(-1). We find that HL-LHC may probe doubly charged scalars masses up to 2.3 TeV, whereas HE-LHC can impressively probe masses up to 3 TeV, conclusively constituting a complementary and important probe to signs of doubly charged scalars in lepton flavor violation decays and lepton-lepton colliders.