Speaker
Description
LHCb has recently submitted a document describing the physics case for
Upgrade II of the detector to begin operation in 2031.
The Upgrade II of LHCb is planned to run at an
instantaneous luminosity of 2×1034 cm−2s−1, an order of
magnitude above that of Upgrade I, which will be commissioned in 2021.
The goal of Upgrade II is to accumulate a sample of at least 300 fb−1 in about 5 years.
At this luminosity the mean number of interactions per crossing will be 56,
producing around 2500 charged particles within the LHCb acceptance every bunch crossing.
To meet this challenge it is foreseen to modify the existing spectrometer, exploiting precision timing in the event reconstruction.
The LHCb upgrade physics programme relies in particular on an efficient
and precise vertex detector (VELO). The higher luminosity poses significant
challenges and require the construction of a new VELO with enhanced
capabilities. Compared to Upgrade I there will be an order of magnitude
increase in data output rate and hence also an order of magnitude increases in
radiation levels, giving a lifetime fluence of nearly 1×1017 1 MeV neqcm−2.
Similarly to Upgrade I, the next detector generation will not have a trigger at
the hardware level, and event selection will be done by complete event
reconstruction in real time in a CPU farm. To cope with the large increase in
pile-up, new techniques to efficiently assign each b-hadron to the primary
vertex from which it originates are needed.
Therefore a new hybrid pixel detector with enhanced rate and timing
capabilities in the ASIC and sensor will be developed.
The most promising technologies to be used for this future HL-LHCb upgrade will
be presented, with emphasis on the timing precision as a tool for vertexing in
the next generation detectors. The most recent results from beam tests,
focussing on time measurements, will be shown together with possible R&D
scenarios for the future upgrade.
