1. LHCb Upgrade – P Collins Beauty 09, Heidelberg
LHCb on the eve of the LHC
LHCb upgrade
The physics programme
NP opportunities at LHCb (10 fb-1) and beyond
The data taking opportunity
Increasing statistics by a factor 10-20
The hardware challenge
Detector modifications needed
Schedule and Conclusions
Paula Collins (CERN)
On behalf of the LHCb collaboration
09/09/09
LHCb Upgrade – P Collins Beauty 09, Heidelberg

2. LHCb: The Day 1 Experiment
bb production correlated and sharply peaked forward-backward
Single-arm forward spectrometer : mrad
σbb ~ 500 µb in LHCb acceptance
Production of B+, B0, B, b-baryons..,
LHCb runs at L= cm-2s-1 by not focusing the beam as much as
ATLAS and CMS
maximizes probability of a single interaction per crossing
LHCb will go immediately to design luminosity
LHCb in numbers
Mass resolution: 14 MeV
Time resolution: 40 fs
IP resolution: /pT mm
PID over GeV
~ bb pairs produced per year
Trigger goes from 40→1 MHz in hardware, then to 2kHz in software
09/09/09
LHCb Upgrade – P Collins Beauty 09, Heidelberg

3. LHCb: in design And in reality Muon HCAL ECAL RICH2 Tracker Magnet TT
VELO
Outer/Inner Tracker 3 3 3

4. LHCb 10 fb-1 NP physics highlights
Rare decays: Bs  µµ
Direct search for NP
3s measurement of SM prediction
Mixing phase in Bs  J/yf (tree)
Sensitive to NP in mixing
Measure s (fs) ≈ 0.01
Mixing phase in Bs  ff (penguin)
Sensitive to NP in loops
Measure phase ≠ 0 (=NP) with s ≈ 0.035
CKM angle g from Bd  D/DK, Bs→DsK, Bd->Dp (tree)
Determine standard candle against which NP sensitive measurements can be compared
measurements to ~ 2° degrees
Santos
CKM angle g from Bd(s)→pp, KK (penguin), B→hhh
g_NP vs g_SM
Sensitive to ≈ 3° degrees
CPV in penguins Bdf Ks : b vs beff
Sensitive to NP in loops
Sensitive to ≈ 0.1
Search for RH currents in radiative decays Bs f g ; Asymmetry FB of Bd  K* µµ
zero of AFB(s) to 7%
D meson physics
CPV, D-D mixing, rare decays e.g. D0→mm
Carson
Leroy
Leroy
Reece,
Belyaev
Ricciardi
Magnin
09/09/09
LHCb Upgrade – P Collins Beauty 09, Heidelberg

5. Why upgrade? Or, Why Should We Fully Exploit LHCb b production?
There are hints of NP being just around the corner. If they are confirmed by LHCb e.g. in Bs→J/yf then the path forward is clear and the precision measurements must be pursued
If ATLAS/CMS discover NP, but the effects are more subtle in the flavour sector then we will need precise measurements to test predictions
Pursue channels statistically limited at current experiment e.g. Bs→ff
Keep pace with theoretical predictions which will improve with time e.g.
e.g. indirect precision on g
2010: sg ~ 5o
>2015: sg ~ factor 5 better thanks to significant improvements from lattice QCD?
arXiv: v33

6. Pushing the Precision Frontier
fs=-0.0360.002 rad one of the most precisely predicted CPV quantities in the standard model
If NP in the Bs sector turns out to be large, then LHCb upgrade will be needed
If it turns out to be small (as appears to be the case in the Bd sector) then precise measurement is needed to match clean prediction
LHCb (J/y f )
Upgrade (J/y f ) SM s
0.01
~0.003
0.002
LHCb numbers are with J/y f alone
Precision will be even better with other channels e.g. J/y fo(pp)
Direct proportionality to η leads to
interesting constraint on UT
LHCb precision, 10 fb-1
09/09/09
LHCb Upgrade – P Collins Beauty 09, Heidelberg

7. b→s penguins, a very promising place for NP to lurk
Bs0→ff dominated by penguins: NP can enter in mixing box and/or in penguins CP violating asymmetry is zero, due to cancellation of mixing and decay phases
At upgrade 0.6M events and error of 0.01
Intriguing pattern emerging,
but existing precision poor
LHCb and upgrade will clarify this picture
Can be complemented by B0→fKs0 and family:
At the upgrade we expect events and a precision of 0.02
09/09/09
LHCb Upgrade – P Collins Beauty 09, Heidelberg

8. Bs →mm and Bd →mm – an exciting future
SM prediction is precise, and small!
Blanke et al, JHEP 0610:003, 2006
This can be reached with 10fb-1 at LHCb.
If NP gives significant enhancements then will be seen sooner!
However:
Certain models, e.g. MCPVMFV, can give enhancements but can also suppress the branching ration < SM depending on phases
Need more statistics than available at baseline LHCb 10fb-1 to approach SM 10% precision
Rate of (Bd/Bs)→mm tightly constrained and can distinguish SM and MFV (Buras: hep-ph/060405). Might Bd→mm be visible at upgraded LHCb???
09/09/09
LHCb Upgrade – P Collins Beauty 09, Heidelberg

9. LHCb Upgrade – P Collins Beauty 09, Heidelberg
B → K0* l+l-
Powerful NP laboratory
Host of interesting observables. Angular distributions e.g. forward-backward asymmetry of the angle between lepton and B in the dilepton rest frame
Position of zero asymmetry crossing point will be measured by LHCb as well as needed, but many other theoretically clean observables will only come into play with > 10 fb-1
0.35 M yield at upgrade 100 fb-1
Egede, JHEP11 (2008) 32
With larger statistics, study of further observables (transverse asymmetries: AT(2) , AT(3) , AT(4) ) sensitive to NP
09/09/09
LHCb Upgrade – P Collins Beauty 09, Heidelberg

10. LHCb 10 fb-1 NP physics highlights
Rare decays: Bs  µµ
Direct search for NP
3s measurement of SM prediction
Mixing phase in Bs  J/yf (tree)
Sensitive to NP in mixing
Measure s (2bs) ≈ 0.01
Mixing phase in Bs  ff (penguin)
Sensitive to NP in loops
Measure 2bseff ≠ 0 (=NP) with s ≈ 0.03
CKM angle g from Bd  D/DK, Bs→DsK, Bd->Dp (tree)
standard candle against which NP sensitive measurements can be compared
measurements to ~ 2° degrees
Santos
CKM angle g from Bd(s)→pp, KK (penguin), B→hhh
g_NP vs g_SM
Sensitive to ≈ 3° degrees
CPV in penguins Bdf Ks : b vs beff
Sensitive to NP in loops
Sensitive to ≈ 0.1
Search for RH currents in radiative decays Bs f g ; Asymmetry FB of Bd  K* µµ
(zero of AFB(s) to 7%)
D meson physics
CP, D-D mixing
Carson
Leroy
Leroy
Reece,
Belyaev
Ricciardi
Magnin
09/09/09
LHCb Upgrade – P Collins Beauty 09, Heidelberg

11. LHCb 10 fb-1 NP physics highlights
Upgrade
Rare decays: Bs  µµ
Direct search for NP
3s measurement of SM prediction
Mixing phase in Bs  J/yf (tree)
Sensitive to NP in mixing
Measure s (fs) ≈ 0.01
Mixing phase in Bs  ff (penguin)
Sensitive to NP in loops
Measure phase ≠ 0 (=NP) with s ≈ 0.03
CKM angle g from Bd  D/DK, Bs→DsK, Bd->Dp (tree)
standard candle against which NP sensitive measurements can be compared
measurements to ~ 2° degrees
Santos
CKM angle g from Bd(s)→pp, KK (penguin), B→hhh
g_NP vs g_SM
Sensitive to ≈ 3° degrees
CPV in penguins Bdf Ks : b vs beff
Sensitive to NP in loops
Sensitive to ≈ 0.1
Search for RH currents in radiative decays Bs f g ; Asymmetry FB of Bd  K* µµ
(zero of AFB(s) to 7%)
D meson physics
CP, D-D mixing, rare decays
Carson
Measure BR to ~5-10%, search for Bd  µµ
Improve by factor 4-5
Leroy
Improve by factor 3:
Level of indirect prediction
Comparison at 0.03o level
Leroy
Reece,
Belyaev
Measure to s≈0.01, pin down NP
New observables to improve NP sensitivty
Ricciardi
Magnin
Measure and characterise CPV
sub-degree precision
09/09/09
LHCb Upgrade – P Collins Beauty 09, Heidelberg

12. To extend the physics programme, why not just turn up L?
LHC is (will be) capable of delivering to LHCb ~50% of the L delivered to the GPDs – would be more than good enough!
Baseline scenario: increase our luminosity from to 2x1033cm-2s-1
Crossings with ≥ 1 interaction 10 MHz → 30 MHz
Average number of interactions per crossing 1.2 → 4.8
Spillover: increases linearly with L
Compatible with SLHC Ihigh x Ilow scenario
BUT, it’s all about the trigger!
Level-0: Largest ET hadron, e(g) and m
1MHz read-out rate is currently the bottle neck in the system
m channels: yield proportional to L
Hadronic channels: If we increase L we have to increase our ET cut and there is no net efficiency gain!
Our current 2.5 us latency is inadequate for a trigger decision of this complexity
09/09/09
LHCb Upgrade – P Collins Beauty 09, Heidelberg

13. LHCb upgrade strategy = Move to a full software trigger
The idea
The consequence:
Read out all sub-systems
at 40 MHz
The consequence
Aim to operate at L=2.1033
Perform entire trigger on
CPU farm with input rate 30 MHz
Goal is to double trigger efficiency for hadronic channels and make the yield scale with luminosity
All subsystems must be fully read out at 40 MHz
Replace most FE electronics, silicon modules, RICH HPDs, FE boards of calorimeter and outer tracker
Replace all FE-electronics; all silicon modules, RICH-HPDs, FE boards of Calorimeter, Outer Tracker FE
Trigger uses ALL event information, reconstructs all primary vertices, and can cut on pT for high i.p.
Preliminary studies show that the hadron efficiency will improve by ~2, and yield will be proportional to L
Increase in statistics x20 for hadronic channels and x10 for leptonic channels
This gives the additional flexibility to adapt to the physics landscape in the next decade
Case study: Bs  ff (after HTL1)
L = 2x1032 cm-2s-1
ET> 3.5 GeV  e ≈ 22%
Min.Bias retention 10 kHz
L = cm-2s-1
ET> 2 GeV  e ≈ 45%
Min.Bias retention 28 kHz
09/09/09
LHCb Upgrade – P Collins Beauty 09, Heidelberg

14. LHCb Upgrade – P Collins Beauty 09, Heidelberg
LHCb Upgrade TimeLine
First upgrade workshop Jan ‘07 Edinburgh
EOI submitted April ‘08
Upgrade task force formed
TDR planned for 2010
Plan to:
Accumulate LHCb in 5 years
Install substantial upgrade in (in synch with machine shut downs and long GPD interventions)
Extract from EOI LHCb
09/09/09
LHCb Upgrade – P Collins Beauty 09, Heidelberg

15. Detector Environment @ Upgrade
Radiation:
Current detector designed to withstand 20 fb-1
Affects mainly large h (trackers, inner part of calorimeter)
Running experience needed
Note that VELO in any case will be replaced
B yield from tracking efficiency
(no spillover)
Tracking and Occupancy:
Si can be operated without spillover: giving occupancy increase of ~2
Outer tracker straws: occupancy too high:
Increase area coverage of IT and use faster gas
Move to scintillating fibres
Material Budget an important issue (occupancy, momentum resolution)
Luminosity (1032 cm-2s-1)
09/09/09
LHCb Upgrade – P Collins Beauty 09, Heidelberg

16. Vertexing @LHCb Upgrade
Upgrading the VELO to 40 MHz implies complete replacement of all modules and FE electronics.
Two major challenges
Data rate of ~1300 GBit/s
Radiation levels and hence thermal management of modules
Important to maintain current performance by keeping material low
Small modules with low power
Thinning of sensor and electronics
Use of CVD diamond planes for cooling and/or sensor
Removal/rework of RF foil
Dose after 100 fb-1
500
neqcm-2 x 1016
TID (MRad) 50 5
Radius (cm)
tip of current VELO
09/09/09
LHCb Upgrade – P Collins Beauty 09, Heidelberg

17. Vertexing @ LHCb upgrade
Candidate module designs
Strip solution
Small inner radius
Thin sensors
Diamond cooling plane
New electronics needed
Occupancy 1-2%
strip
pixel
Pixel Solution
Low occupancy helps for PR and timing
TIMEPIX (55x55 mm) is a promising candidate for FE electronics
square pixel and buttable design allows single layer construction
Modification needed to architecture
Testbeams this summer show excellent performances
Timepix: 55 mm pitch
PRELIMINARY
Residual (micron)
Estimated track contribution to residual 2.5 mm
Track angle (degrees)
09/09/09
LHCb Upgrade – P Collins Beauty 09, Heidelberg

18. Tracking @ LHCb upgrade
2x1032 cm-2s-1
OT Occupancy
75 ns gate
50 ns gate
High Luminosity will produce high occupancy and ghosts in the tracking system
particularly in the Outer Tracker where a gas technique is used (drift time in straw tubes) and signal is collected in ns
The area coverage of the Inner Tracker has to be increased, along with new sensors, new FE chip
Full silicon tracker in front of magnet must be rebuilt
Finer pitch? More layers?
Material budget is an important issue
Critical for momentum resolution and PR
Also: Radiation/cooling
OT+IT
09/09/09
LHCb Upgrade – P Collins Beauty 09, Heidelberg

19. Alternative Solutions19 OT IT
A fiber tracker with mixed fiber dimensions (250 mm for inner part, mm for outer) to be readout with SiPM and/or conventional MaPMT
Simplified services configuration: no cables, no cooling, frames thinning, FEE outside  gives less X/X0
Good timing performances
Increased granularity in x – spatial resolution enough
Problems to be addressed:
SiPM readout and its optimisation
radiation hardness
mechanics
32 channels Si PM: 0.25 x 1 mm2
Lausanne
Preliminary: 80 mm residuals

20. Particle ID in the RICH system
Need to replace front end electronics AND photon detectors to cope with 40 MHz readout
Baseline approach; keep current geometrical layout RICH1 (aerogel+C4F10) + RICH2 (CF4)
OR, replace aerogel with new TOF system (TORCH) located after RICH2
Photon sensors together with their new (independent) chip are the critical item:
could be MaPMT
0.3M channels
R&D needed (x talk, spillover, B field, lens...)
or upgraded HPDs
study ion feedback rate
many new components: production time an issue
or MCPs
B tolerance, timing, new idea...
Next generation MaPMTs
Example PID
over full momentum
range with TORCH

21. New concept for RICH: the TORCH
Time of flight detector based on a quartz plate, for the identification of p<10 GeV hadrons (replacing aerogel)
reconstruct photon flight time and direction in specially designed standoff box
Clock arrival time to ~20 ps
Deduce photon emission time → track ToF
R&D on hardware needed:
Microchannel plate PM with multianode readout
MCP-PM achieved in testbeam ps time resolution with p.e.
mechanics, electronics (Timepix?), aging etc.
possible synergy with PANDA and VELO
aerogel expected to give marginal photon yield and its use will become challenging with the higher occupancy of the upgrade
contributes material in the tracking volume
provide low momentum coverage with new torch detector decoupled from the RICH system
Micro Channel Plate PMT : flat photocathode with MCP to amplify electron image before collecting charge in anode of device
25 micron pore good for us but 8x128 segmentation needed
front end electronics an issue
synergy with PANDA who have similar deveopments
E.Ramberg /TIPP09

22. Calorimeters 22
September 2009: calorimeter
modules placed in LHC tunnel
to accumulate dose
HLT seeds already provided at 40 MHz
Modifications to electronics needed:
Upgraded FE boards
Lower PM gain (÷5) and increase preamp sensitivity and lower noise accordingly
No showstopper foreseen
Radiation tolerance currently an open issue
Affects inner part of ECAL (would need replacement)
Tested up to 2.5 Mrad (1 upgrade year)
R&D underway to collect more comprehensive data
Pile-up (~4 at upgrade) will affect resolution: watch carefully for low pT, g physics
Resolution
2x1032 cm-2s-1
Q varying
2x1033 cm-2s-1
Energy

23. Muon System Maximum rates per channel at 2.1033 R23
Muon System
Maximum rates per channel at
FEE readout already at 40 MHz
Two main concerns:
dead time due to high rate in inner regions
aging due to radiation in inner regions
An evaluation of these effects will come
from first data R z
Accumulated chage (C/cm) on wires for 100 fb-1 R z
Possibility of replacement of the inner parts with large area GEM
(70x30 cm2) or with MWPC, in any case with new, smaller pad readout
M1, due to background and to upgraded L0, will be removed
A transition to a fully 3D muon projective readout
(and not based on strips crossing) could reduce the
fake associations (detailed studies to be performed)

24. LHCb Upgrade – P Collins Beauty 09, Heidelberg
Outlook
LHCb commissioning is well underway
On course to accumulate 10 fb-1 in ~ 5 years
Upgrade strategy SLHC independent:
Goal: 100 fb-1 in 5 years at L=2x1033
X20 statistics in hadron channels
X10 statistics in leptonic channels
Maintain tracking and PID performance
Upgrade TDR out in 2010
09/09/09
LHCb Upgrade – P Collins Beauty 09, Heidelberg

25. LHCb Upgrade – P Collins Beauty 09, Heidelberg
Homing in on g
Interferences between the bc and bu tree transition for B-(D°/D°)K-
Example : Dalitz analysis of D°/D°Ksππ to extract (rB,δB,γ) B- B+
Here D final state is common to D and Dbar, many possibilities. Want to exploit
As many modes as possible but each decay brings its own strong phase
Difference which needs to be known
Precision of 3-3 deg with 10 fb-1?
Amplitude fit, model error 7o
Binned fit, CLEO-c error 2o
Binned fit, CLEO-c error 5o
09/09/09
LHCb Upgrade – P Collins Beauty 09, Heidelberg