High Luminosity Large Hadron Collider

The High Luminosity Large Hadron Collider (HL-LHC; formerly SLHC, Super Large Hadron Collider) is an upgrade to the Large Hadron Collider started in June 2018 that will boost the accelerator's potential for new discoveries in physics, starting in 2026. The upgrade aims at increasing the luminosity of the machine by a factor of 10, up to 1035 cm−2s−1, providing a better chance to see rare processes and improving statistically marginal measurements. The High Luminosity Large Hadron Collider (HL-LHC; formerly SLHC, Super Large Hadron Collider) is an upgrade to the Large Hadron Collider started in June 2018 that will boost the accelerator's potential for new discoveries in physics, starting in 2026. The upgrade aims at increasing the luminosity of the machine by a factor of 10, up to 1035 cm−2s−1, providing a better chance to see rare processes and improving statistically marginal measurements. Many different paths exist for upgrading the collider. A collection of different designs of the high luminosity interaction regions is being maintained by the European Organization for Nuclear Research (CERN).A workshop was held in 2006 to establish which are the most promising options. Increasing LHC luminosity involves reduction of beam size at the collision point and either reduction of bunch length and spacing, or significant increase in bunch length and population. The maximum integrated luminosity increase of the existing options is about a factor of 4 higher than the LHC ultimate performance, unfortunately far below the LHC upgrade project's initial ambition of a factor of 10. However, at the latest LUMI'06 workshop, several suggestions were proposed that would boost the LHC peak luminosity by a factor of 10 beyond nominal towards 1035 cm−2s−1. The resultant higher event rate poses important challenges for the particle detectors located in the collision areas.