LHCb upgrade plans

The LHCb experiment will operate for about five years at a luminosity of 2 x 10$^{32}$ cm$^{-2}$s$^{-1}$ and plans are to accumulate a data sample of ~10 fb$^{-1}$. Here we present the physics programme and detector design for a future high luminosity phase of the LHCb experiment. An upgraded LHCb experiment would operate at ten times the design luminosity, i.e. at ~2 x 10$^{33}$ cm$^{-2}$s$^{-1}$ and aims to collect a data sample of ~ 100 fb$^{-1}$ over five years. This programme would allow the probe of new physics at an unprecedented level. Key measurements include the $B^0 _s$ mixing phase $\phi_s$ in $B^0_s \to J/\psi \phi$ and $B^0_s \to \phi \phi$ decays with a significant sensitivity to the small Standard Model prediction and a very precise measurement of the CKM angle $\gamma$ in three diagram decays. Initial studies of the modified LHCb trigger and detectors are presented. The upgraded LHCb experiment can run with or without an LHCb luminosity upgrade.