The LHCb Upgrade Programme

This paper will describe the upgrade programmes of the LHCb experiment at the LHC, and the current construction and installation status. The LHCb experiment at the LHC is designed to capture decays of b- and c-hadrons for the study of CP violation and rare decays. It has already had a transformative impact in the field of flavour physics as well as making many general purpose physics measurements in the forward region. At the end of Run-II, many of the LHCb measurements will remain statistically dominated. For this reason the experiment is being upgraded in a first step, dubbed Upgrade I, to run at five times higher luminosity from 2020. The trigger scheme, which currently has a 1 MHz lowest level hardware rate, will be transformed to a strategy whereby the entire experiment is read out at 40 MHz to a software trigger. The increased luminosity and trigger efficiency anticipated at the upgrade will allow a huge increase in precision, in many cases to the theoretical limit, and the ability to perform studies beyond the reach of the current detector. In addition the flexible trigger and unique acceptance opens up opportunities in topics apart from flavour, reinforcing the role of LHCb as a general purpose detector in the forward region. In order to allow the triggerless readout the front end electronics of all subdetectors will be changed, and many subdetectors will be upgraded to cope with the increased occupancy and radiation levels. During the long shutdown between Run 3 and Run 4 the most irradiated parts of the detector will be replaced and other detector consolidation and improvement steps will be carried out. A further major upgrade, dubbed Upgrade II, is proposed for installation during the LHC long shutdown 4. Here major parts of the detector will be replaced and functionality added to enable the detector to run at a further luminosity step of up to 10 times higher than in Upgrade I. It is anticipated to collect more than 300 inverse femtobarn of data at Upgrade II.