Will LHCb be running during the HL-LHC era? Burkhard Schmidt for the LHCb Collaboration

Transcription

1 Will LHCb be running during the HL-LHC era? Burkhard Schmidt for the LHCb Collaboration Helpful discussions with L. Rossi and several other colleagues from the machine acknowledged Outline: Introduction and Physics Motivation LHCb Detector and Trigger Upgrade Machine related issues to the LHCb upgrade Conclusions YES

2 LHCb believes there is a strong case for continuing to run beyond LS2 in We appreciate that at fixed luminosity the data-doubling time will become long, so we consider it essential to upgrade the experiment to increase the signal rate to storage by an order of magnitude. The physics case for 50 fb-1 in LHCb has been presented in detail to the LHCC in a Letter of Intent and endorsed by them. The evidence for CP violation in the charm sector is one of the most important and unexpected results to have come from the LHC so far, and illustrates the potential of probing for new physics in the flavour sector. B. Schmidt LHC performance workshop Chamonix

3 LHCb performs precision measurements of CP asymmetries and investigates potential effects of physics beyond the Standard Model. Discover New Physics through indirect effects of new states via virtual production in loop diagrams. Sensitive far beyond direct particle production reach The LHCb physics program is complementary to the direct searches of ATLAS and CMS. complementary to the physics program of Super-B factories. LHCb contributes to the diversity of the CERN Physics program. B. Schmidt LHC performance workshop Chamonix

4 World Best Example: Φ s : the B s mixing phase Mixing induced CP-Violation in B s Obtained compelling results from initial measurements Tevatron SM discrepancy resolved Precision measurements challenging in the forward region at a hadron collider Need luminosity Need a detailed understanding of detector & systematics Until 2017 (Phase I) : Upgrade (from 2019): Observe NP in ϕ s if larger than 3 x SM Beyond SM precision measurement: σ B. Schmidt LHC performance workshop Chamonix

5 software hardware Present Trigger 40 MHz Level-0 μ, had, e, γ Max 1 MHz HLT1 part. recon. HLT2 global recon. 3-4 khz Storage: event size ~50kB Final states with muons Linear gain Hadronic final states Yield flattens out Must raise p T cut to stay within 1 MHz readout limit To profit of a luminosity of 2 x10 33 cm -2 s -1, information has to be introduced that is more discriminating than E T. Upgrade strategy: 40MHz readout rate Fully software trigger 20kHz output rate B. Schmidt LHC performance workshop Chamonix

6 LHCb Upgrade L = 2 x10 33 /cm 2 /s collect > 50 fb -1 ~5 fb -1 /year s =14TeV Calorimeters: replace R/O Muon System; allmost compatible New Silicon Tracker New Vertex Detector Outer Tracker: replace R/0 TORCH RICH: change HPD s to MAPMT s Physics program: Wide range with quark flavour physics as main component, but includes also lepton flavour physics, electroweak physics and exotic searches General purpose detector in the forward region with 40 MHz readout and a full software trigger. B. Schmidt LHC performance workshop Chamonix

7 The Physics program of LHCb is limited by the detector, not by the LHC. The detector upgrade allows LHCb to better utilise the LHC capabilities. The LOI for the upgrade has been submitted in March 2011 and endorsed by the LHCC in June LHCb has been encouraged to proceed preparing TDRs. LHCb intends to upgrade the detector in LS2, scheduled for 2018, and to take data for about 10 years afterwards. B. Schmidt LHC performance workshop Chamonix

8 LHCb design: L ~ 2x10 32 cm -2 s -1 at s of 14TeV with 25 ns BX interactions / bunch crossing µ = 0.4 LHCb operation in 2011: L up to 4 x cm -2 s -1 at s of 7 TeV with 50 ns BX µ = 1.6 LHCb upgrade: L > 2 x cm -2 s -1 at s of 14TeV with 25 ns BX With 50ns BX the average pile-up would be up to 8, which leads to a too large detector occupancy 25 ns LHC operation is fundamental for the LHCb upgrade µ = 4 B. Schmidt LHC performance workshop Chamonix

9 Target Absorber for Secondaries (TAS): The high luminosity insertions at IP1 and IP5 are equipped with a TAS and a TAN to protect the triplet quadrupole magnets and other machine elements from particles leaving the IP. Would a TAS/TAN be needed in IP8 for the envisaged luminosity increase to 2 x /cm 2 /s? Good knowledge of BLM thresholds around IP8 is important. Detailed FLUKA simulations are needed. A first glance at the issue of the TAS: Look at beam losses up- and down-stream of IP8 for a fill in 2011 where the luminosity has been 4x10 32 /cm 2 /s in LHCb (at s of 7 TeV). Factor 5 below maximum luminosity for the upgrade, and factor 2 less in energy Factor 4 is needed to take into account the difference between L peak and L Level How far are we from the threshold causing a beam dump? (which is at ~30% of the quench limit) B. Schmidt LHC performance workshop Chamonix

10 Fill 2242 on October 23/24, 2011 L = 4x10 32 /cm 2 /s BLM RS12=1.5x10-6 Gy/s Courtesy Mariusz Sapinski B. Schmidt LHC performance workshop Chamonix

11 Running Sum 12 (84s) for beam loss signal averaged over 5 hours luminosity of 4 x /cm 2 /s beam 1 beam 2 Dump limit Courtesy Mariusz Sapinski Q4 D2 BLM close to beamline D1 Q3 Q2 Q1 LHCb The losses are a factor or more below the dump threshold Better knowledge of BLM thresholds is important. B. Schmidt LHC performance workshop Chamonix

12 R2E issues (M.Brugger): Relocation of some equipment is foreseen in LS1. More simulations are needed to determine whether other equipment needs to be mitigated. Cable length to be checked. Safe room needs to be reviewed. Aperture and Beam-Screen (LBOC 24.o1.12, R. Bruce et al.): Beam screen orientation is optimized for external horizontal crossing angle. Move to vertical crossing angle this year Aperture should give no problems at top energy Aperture at injection more problematic 450 GeV, beta*=11m, 170urad H 3.5 TeV, beta*=3m, 100urad V Rotation of the beam-screen in the triplet by 90 o in LS1 would be desirable x m y m B. Schmidt LHC performance workshop Chamonix TeV, 3.5m, sep 2mm, 1

13 LHCb submitted an LOI to the LHCC in March 2011 and has a firm plan to upgrade the detector by 2018 LHCC considers the physics case compelling and the 40 MHz readout as the right upgrade strategy. LHCC encouraged LHCb to prepare a TDR as soon as possible. Given its forward geometry, its excellent tracking and PID capabilities and the foreseen flexible software trigger, the upgraded LHCb detector is an ideal detector for the next generation of flavour physics experiments provides unique and complementary possibilities for New Physics studies. LHCb intends to run for about 10 years after the upgrade and relies on 25 ns LHC operation, luminosity levelling, equal amounts of data for the two spectrometer magnet polarities. First discussions with the machine in relation to the upgrade took place and we intend to continue them in view of the TDRs under preparation. B. Schmidt LHC performance workshop Chamonix

14

15 L= 4x10 32 /cm 2 /s BLM~ 1.5x10-6 Gy/s BLM in cell 5 (follows the beam intensity) Courtesy Mariusz Sapinski B. Schmidt LHC performance workshop Chamonix

16 Running sum 12 (84s) for beam loss signal averaged over 5 hours in fill 2242 on October 23/24 with stable luminosity of 4 x /cm 2 /s beam 1 beam 2 Dump limit Courtesy Mariusz Sapinski LHCb Q1 Q2 Q3 D1 D2 Q4 The losses are a factor or more below the dump threshold B. Schmidt LHC performance workshop Chamonix

17 TAS: Space is very tight due to compensator magnets (on both sides). TAN: The situation is much better space wise. MBXW TCDD/TDI MKI MSI B. Schmidt LHC performance workshop Chamonix