1. T. Bowcock University of Liverpool For the LHCb Collaboration
The LHCb Experiment
T. Bowcock
University of Liverpool
For the LHCb Collaboration

2. Overview Detector Design LHCb Components and Status Physics Summary
2/24/2019
LHCb Detector
T. Bowcock

3. Detector Design(1) Goals
Simultaneous measurements of ,,, and 
Exploration of Bs sector
Access to rare b-decays +…
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LHCb Detector
T. Bowcock

4. Detector Design(2) 1 r h a g b
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LHCb Detector
T. Bowcock

5. Detector Design(3) Forward Physics
O(1012)bbpairs/year
bb~500b
bb/ inelastic~5×10-3
Pairs produced at small angles
Modest luminosity
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LHCb Detector
T. Bowcock

6. LHCb(1) Components
Reversible field
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LHCb Detector
T. Bowcock

7. LHCb(2) Particle ID ID 1-150GeV/c
RICH system divided into 2 detectors and 3 radiators: aerogel, C4F10, CF4
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LHCb Detector
T. Bowcock

8. LHCb(3) RICH Acceptance 300 mrad RICH 1 120 mrad RICH 2
Radiators: thickness L, refractive index n, angle c, /K threshold
Aerogel C4F10 CF4
L cm n
qc mrad
p GeV
K GeV
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LHCb Detector
T. Bowcock

9. LHCb(4) Particle ID 3s separation pK 3-80GeV/c
# of detected photons
7 Aerogel C4F CF4
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LHCb Detector
T. Bowcock

10. LHCb(5) Particle ID Bd   + (a) Bs  DsK (g) 2/24/2019
LHCb Detector
T. Bowcock

11. LHCb(6) Vertexing
VELO
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LHCb Detector
T. Bowcock

12. LHCb(7) VELO
Series of disks
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LHCb Detector
T. Bowcock

13. LHCb(8) VELO Micron pn&nn Rad tolerant High resolution
Xs ~ 80
200,000 channels
Low occupancy
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LHCb Detector
T. Bowcock

14. LHCb(9) Trigger
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LHCb Detector
T. Bowcock

15. LHCb(10) Trigger
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LHCb Detector
T. Bowcock

16. LHCb(11) Status LHCb Experiment Approved Sep 1998
Technical Design Reports
Magnet
Calorimeter
Muon
RICH
VELO
Outer Tracker
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LHCb Detector
T. Bowcock

17. LHCb(12) Improving Performance
Reducing Material Budgets
VELO X0 0.04
RICH X0 0.05
Tracking X0 0.11
Beam Pipe
VELO: material, stations
RICH: Mirror
Tracking Stations
Trigger efficiencies
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LHCb Detector
T. Bowcock

18. Physics(1) 2005
BABAR, BELLE
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LHCb Detector
T. Bowcock

19. Physics(2) LHCb 2007/8
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LHCb Detector
T. Bowcock

20. Physics(3) LHCb Performance
Sensitivity
Relative to LHCb 1 year operation
Atlas/CMS
(1 year)
BABAR
0.5ab-1
BTeV
LHCb
(Value)
s(Sin2b)Expt/s(Sin2b)LHCb
0.9/0.8
2.6
1.8
0.02
s(Sin2a)Expt/s(Sin2a)LHCb
1.8/3.0
3.2
0.4
???
s(g)Expt/s(g)LHCb -
1.0
10
s(-2dg+g) Expt /s(-2dg+g) LHCb
1.2
1.6/1.8 75
4.2
2.0
25K
1.2/1.6 33
Physics(3) LHCb Performance
2/24/2019
LHCb Detector
T. Bowcock

21. Summary Second generation b-physics experiment “day-one” operation
Superb instrument for exploring possible deviations from SM in B sector
Preparation progressing well
2/24/2019
LHCb Detector
T. Bowcock