LHCb upgrade status

1. LHCb upgrade status G. Auriemma Università degli Studi della Basilicata and INFN Sezione di Roma Muon Upgrade meeting CERN, January 15,2009

2. Major events • Collaboration Upgrade Workshop (Edinburgh January,11-12 2007) • EOI submitted to LHCC on April,22 2008 (CERN/LHCC/2008-007) • “Upgrade WG II” (coordinated by Sheldon Stone) for TP preparation appointed in the November 2008 LHCb-Week G. Auriemma

3. Physics motivations for the upgrade • Search for New Physics in CPV measurements • Search for New Physics in Rare decays • CP violations in charm • Possibly other exotics (TBD): • Non Standard Higgs decays • CPT Violations • Dark matter particles • … G. Auriemma

4. No NP LHCb sensitivities for integrated lumi of 100 fb-1 Presentation to SPC SLHC Assessment (A. Golutvin) G. Auriemma

5. Two step upgrade • Required to follow machine schedule • First step : run at 1033 with minimal, but significant changes specially in electronics and Si detector • Second step: many detector upgrades to maximize physics reach & run at ≥2x1033 G. Auriemma

6. Planning (~ April 2008) 3 MeV test place ready Linac4 approval CDR 2 Start for Physics SPL & PS2 approval L. Evans talk at http://indico.cern.ch/conferenceOtherViews.py?view=standard&confId=30583 G. Auriemma

7. Multiple interactions • Note that increasing the luminosity from 2\to10\times10^{32} will only increase the mean number of interactions per crossing by a factor two (data rates from 10 MHz \to26 MHz); • The increase of occupancy for the detectors which are only sensitive to pileup is minimal; • Spill-over increases linearly with luminosity. G. Auriemma

8. Detector Performance vs Luminosity • Tracking • Efficiencies and Ghost rate • Preliminary studies show thatLHCb detectors can operate up to 1x1033 • Detectors designed for 20 fb-1 (except VELO: 6 to 8 fb-1) Long Tracks VELO tracks G. Auriemma

9. Detector Performance vs Luminosity Tracking Efficiencies and Ghost rate Long Tracks VELO tracks G. Auriemma

10. Trigger L0 G. Auriemma

11. Conclusions of EOI on the muon system • The major part of the muon detector can very likely operate at 2×1033 for 5 years • Muon detector electronics is already at 40 MHz • Upgrade of M1 station is not required, it will likely be removed • Momentum of muon candidates determined by tracking stations • Ageing tolerable up to 100 fb-1 with the possible exception of region M2R1 • technology presently adopted for region M1R1 (triple-GEM) will work • Further studies are required to understand the effects of a larger occupancy of the muon detector on the tracking and the purity of muon identification. G. Auriemma

12. Ageing for expected low energy bkg. Besides M1, the limit of 1C/cm is trespassed only in M2R1 G. Auriemma

13. Ageing (2) • Prototypes of the triple-GEM detectors have been tested at the CALLIOPE facility of ENEA-Casaccia (near Rome) up to 2.2 C/cm^{2}, with a safe margin. • Prototypes of MWPC chambers have been tested at the level of 0.44 C/cm with no appreciable deterioration of the performances. Ageing will be a serious problem only for the region M1R2, where the safe limit of operation is largely exceeded. Ageing should be acceptable for the rest of the system, with the possible exception of regions M2R1 and M1R3. • However, even if the test done in the technology assessment phase of the MWPC's at the level of 0.5 C/cm give confidence that this type of detector can withstand an exposure of 10\mathrm{fb}^{-1}, it is desirable that those studies are extended to an higher level of charge deposition, before discarding this technology. G. Auriemma

14. Single Rates on the FE • Region M2R1, and perhaps in region M2R2 (if the L.E. bkg. is higher then the MC predictions. • The origin of this problems is the fact that the physical granularity of wire pads wire pads is 6.3x253 mm2. • Possible solutions to be investigated seems to be: • rebuild with GEM-like chambers (e.g. thick-GEM); • rebuild with MWPC with smaller wire pads (difficult); • shield this region from punch-through/showers (?) • some clever electronic trick on FE (?) G. Auriemma

15. Is a rate of ~ 1 MHz at FE tolerable ? • A full scale four-gaps MWPC designed for the region M3R3 built at the INFN Laboratories in Frascati (LNF) has been exposed simultaneously at the 137Cs source of the Gamma Irradiation Facility (GIF) at CERN, which emits 662 keV photons in 85 % of the decays, and the X5 muon beam (Em~100 GeV). • The rate per channel at the LVDS output of the DIALOG, recorded during this test increase with the applied high voltage due to the increasing the multiplication gain that makes the chamber more efficient for the detection of low energy gamma-rays, up to 1.2 MHz/ch. • The test has shown that the efficiency of the chamber is reduced by the presence of low-energy gamma-rays, but this reduction is completely accounted for by the dead-time due to the formation time of the electronics, showing that no space-charge effect and/or other physical effect in the chambers are observed up to this rate. G. Auriemma

16. Dead time calculation assumption • CARIOCA digital output is 50 ns wide • DIALOG one is 25 ns wide. • For correlated signals (i.e signals produced in all the four gaps by a single particle), the dead-time is determined by the CARIOCA output width, while • For uncorrelated signals (i.e. signals produced by particles which fire only one gap, as low energy photons) the dead-time is determined by the DIALOG output width, because only one of the two CARIOCA channels, corresponding to the same DIALOG channel is blind for 50 ns. G. Auriemma

17. Dead time inefficiency Efficiency for physical tracks G. Auriemma