Scenarios for sLHC and vLHC

The projected lifetime of the LHC low-beta quadrupoles and evolution of the statistical error halving time call for an LHC luminosity upgrade by the middle of the coming decade. In the framework of the EU CARE-HHH network, two scenarios have been developed for increasing the LHC peak luminosity by a factor 10, to 10(35) cm(-2)s(-1) (sLHC). Both scenarios imply a rebuilding of the high-luminosity interaction regions (IRs) in combination with a consistent change of beam parameters. However, their respective features, bunch structures, IR layouts, merits and challenges differ substantially. In either scenario luminosity leveling during a store would be advantageous for the physics experiments. Longer-term R&D efforts are devoted to a higher-energy hadron collider (vLHC), which could be realized on a green field or as a later and more radical LHC upgrade.