Possible scenarios for the LHC luminosity upgrade ⁎

We discuss here of the possible scenarios to upgrade the LHC luminosity beyond nominal value of 1034 cm−2s−1. The first step along this way consist in pushing the accelerator parameters to the ultimate performance: by increasing to 1.7 1011 the bunch population, a peak luminosity of 2.3×1034 cm−2s−1 should be eventually made available. To go beyond, a considerable improvement of the LHC parameters, such as β*, beam intensity, bunch length, number of circulating bunches is required. Finally, the upgrade of the injector complex and of the injection energy is another important ingredient to increase both peak and integrated luminosity up to an order of magnitude above the nominal value.