The LHCb Upgrade

With the demonstration that LHCb can successfully perform forward precision measurements with event pileup, the operation and trigger strategy evolved significantly during the LHC Run 1 allowing LHCb to collect over 3fb$^{-1}$ at centre-of-mass energies of 7TeV and 8TeV. Increased bandwidth opened the door for LHCb to extend the physics program. The additional statistics and well managed systematic effects together with the stable trigger and data taking conditions have led to a very large number of world-class measurements and dominance in heavy flavour physics [1], in addition to a reputation of an excellent forward general purpose detector at the LHC. Long Shutdown (LS) 1 (2013-2014) will allow LHCb to fully explore the large statistics collected and prepare LHCb for Run 2 (2015 – 2017). However, even after an additional expected integrated luminosity of 5-6 fb$^{-1}$ in Run 2, many of the LHCb precision measurements will remain limited by statistics, and some exploratory physics modes will not even be accessible yet. With the need for reconstructing the event topology in order to efficiently trigger on the beauty and the charm hadrons decays, the current 1 MHz readout limit is the main bottle neck to run at higher luminosity and with higher trigger efficiencies. LHCb will therefore undergo a major upgrade in LS 2 (2018 – 2019) aimed at collecting an order of magnitude more data by 2028. The upgrade consists of a full readout at the LHC bunch crossing rate (40 MHz) with the ultimate flexibility of only a software trigger. In order to increase the instantaneous luminosity up to 2x1033cm$^{-2}$s$^{-1}$, several sub-detector upgrades are also underway to cope with the higher occupancies and radiation dose.