Proton-driven plasma wakefield acceleration for high-energy lepton beams

Future colliders with discovery potential for particle physics rely on increasing the parton centre of mass (pCM) energy, with the recent P5 report calling for a 10 TeV pCM collider. However, the development of such schemes using conventional accelerator technology would result in ever-larger facilities. High-gradient plasma wakefields driven by proton beams allow the transfer of energy to a witness bunch over a short length scale, and so offer a potential method to transform high-energy proton beams into high-energy lepton beams while requiring relatively little additional civil engineering. The application of this concept to a Higgs factory driven by 400 GeV protons was recently proposed*. In the present work, we discuss the ongoing efforts to address the challenges to realising such a scheme**, and possible upgrade paths to particle physics applications beyond a Higgs factory.