LHC detector upgrade

Abstract

There has already been a study in some depth about the physics reach and the needed upgrades to the LHC experiments, ATLAS and CMS, in the recent past [1]. Subsequently, there were presentations at the CERN ICFA meeting on the accelerator upgrades [2], the detector upgrades [3] and the consequent physics reach [4].

In this note only a brief overview of the detector needs is attempted. If there is a tenfold increase in luminosity (the Super LHC or SLHC). First an example of the increased physics reach using sequential Z bosons is given. The rapidity distribution of heavy states is also illustrated. Then a simple parameterization of the inclusive inelastic, or “minbias”, events is presented.

This model is subsequently used to explore the impact of a tenfold increase in pileup on jet finding and reconstruction at the SLHC. It is also used to estimate the occupancy of tracker elements and the ionization radiation dose sustained by the tracker. Those estimates inform on the shape of possible tracker upgrades for the SLHC and the associated front-end electronics, which must also be upgraded.

The calorimetry of ATLAS and CMS must also be strengthened in order to work at the SLHC. The ATLAS liquid argon and the CMS crystal and scintillator calorimetry are briefly considered. A reduction in forward angular coverage to compensate for the increased radiation field is mentioned. For the muon system a similar reduction in angular coverage would maintain the remainder of the system in a state essentially the same as that for LHC operations. Finally, triggering and data acquisition issues are cursorily discussed.