LHCb

SAC Review MeetingApril 17, 2008Marcel Merk

for the LHCb group

Contents:• Velo and PileUp• Outer Tracker• Software

b-b in LHCb

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LHCb event rate: 40 MHz1 in 160 is a b-b event

• vertices and momenta (mass) reconstruction • effective particle identification (π, К, μ, е, γ)• triggers

qb qb

3

• Silicon strip detector• Reconstruct primary and

secondary vertices• Tracking, use R-Phi geometry• Pile-Up Trigger in L0

The VErtex LOcator in LHCb

Velo “Specials”: Detectors move to 8mm from beam Detectors inside vacuum Cooling with 2-phase CO2

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• Straw tube detector• Momentum determination with

TT and magnet• Tracking, use XUVX geometry• 3 OT stations: T1, T2, T3

The Outer Tracker in LHCb

View of LHCb in Cavern

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VELO

Muon det Calo’s RICH-2 MagnetOT RICH-1

VELO

Muon det Calo’s RICH-2 MagnetOT RICH-1

Installation of major structures is complete

VeLo Project

NIKHEF provides Velo deputy projectleader

Nikhef Contributions:• Mechanics + RF • Vacuum control • Motion control• CO2 cooling• Pile-Up trigger• Commissioning

Collab.: Heidelberg, MPI, Liverpool, Glasgow, CERN, Lausanne, Syracuse, VU, Nikhef

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The Detector Vacuum box (“RF Box”)

30 mm

Thin, leak-tight corrugated RF foil between sensors and beam

Superplastic pressing of 300 mm Al foil with hot gas

Welding into a vacuum tight box

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The Detector Vacuum box (“RF-box”)

Leak rate between beam and detector volumes determined to be : 3.2x10-5 mbar.l/s @ 1 mbar He No problem for normal operation, venting and evacuation Risk: saturation NEG coating during installation Replacement in 2009 R&D ongoing for improved production method

Dp < 5 mbar at all times!

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Half Velo-detector in assembly lab

Operation of both detector halves tested in assembly lab17-4-2008 9

Installation (Oct 2007)

CO2 cooling system

R507a chiller

2-phase

2-phase

cond

ense

r

evap

orat

or

60 m concentric tubepump

rest

rictio

n

accumulatorshielding wall

liquid liquid

VELOdetector

coolingplant

2-phase CO2 cooling system Low mass Radiation hard Redundant / backup system

Only passive components in radiation area Detector temperature (evaporator) is controlled by pressure in accumulator Isothermal because of liquid-vapor mixture

CO2 loop

-25 ‘C

-40 ‘C -25 ‘C

-25 ‘C

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Cooling Plant Installation (summer 2007)

CO2 UnitFreon Unit

Controls PLC

accumulators

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Velo Cooling tests under vacuum

T= -10oC

TRF-foil≈ +9oC

20oC

10oC

0oC

-10oC

-20oC

T (oC)

Time (hours)

Performs well

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Vacuum

During pumpdown and venting: p < 5 mbar between beam-vacuum and detector-vacuum17-4-2008

pdetector

pbeam

T= -10oC

10-8

10-5

10-2

P [mbar]

TRF-foil≈ +9oC

Effect of Cooling on Vacuum

Reach p < 10 -8: OK

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Time

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Velo Commissioning

Outlook Velo (May-June):Power up C-side modules under neonOperate C-side under vacuumRepeat for A-side detector halfThen look forward to beam…

Noise level OK

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All cables and connectors checked (20% LV modules missing)

Cooling, Vacuum and Motion being finalized Hardware interlocks tested

Basic ECS software available, continuously being improved

First R- f station been powered up and read out under bias voltage (80 V):

1717-4-2008

• All detectors/cables/fibers connected– Datapath established (apart from Output Board)

• Final test of connections in May• Implementation in Trigger/DAQ to be worked on

– Test with Level-0 decision unit planned in June• PVSS work ongoing

Hybrids kaptoncables

repeaterboards

transitionboards

opticalboards

VEPROBboards

outputboard

L0DU@IP8

AnalogTell1

digitaltell1

Pile-Up detector

2 dedicated R-stations provide: 1,2,n vertices for each bunch crossing luminosity per time interval

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Outer Tracker ProjectCollab.: Dortmund, Heidelberg, Warsaw, Cracow, Bejing, VU, Nikhef

NIKHEF provides OT project leader

Nikhef Contributions:• Production and Installation: mechanics & electronics• Infrastructure: frames and support bridge• Quality Assurance• Commissioning• Irradiation Studies

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1917-4-2008

Detector Installation - completed

LV,HV, ECS/TFC..

Cooling and Gas

Detector Modules

Alignment: Stations positioned with no x-y-z rotations

to +- 0.5 mm xyz of modules known to +- 0.5 mm Reproducibility of open-close ~ 30 mm

(except 1 C-frame) Final x-alignment of C-frames using RASNIK

(RASNIK installation completes in April)

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OT Electronics . 80% detector is equipped and installed

80% -> 90% is ready for installation

90% -> 100% Produced and tested: May Installed: June

100% -> 110% Finished after summer

C-frame equipped with FE boxes

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OT Commissioning Testing individual channels with a source: 21 bad wires out of 32040 DAQ: OT has been succesfully included in global commissioning runs Cosmics: Cosmic tracks and showers have been observed…

Cosmic trigger in OT

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Ageing Phenomenon

o Gain loss “in the neighborhood”

of the irradiation point:Croissant? Bean? Kidney?

Only at moderate intensity

Upstream of gas flowA real surprise – this was not seen in the aging tests performed over the last years with test modules

Ratio Plot: Iafter/Ibefore

Gas flowCarbon deposit on the surface

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Ageing: The CauseTest module:17 hrs, 2 mCi

Put fresh glue (AralditeAW103, HY991) at straw entrance of Aluminum test module

TraBond 558 hr, 20 mCi

Build full-scale module with different glue: TraBond 2115

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Beneficial Treatments

Flushing Time (weeks)

G

ain

loss

(%)

L

No heating: 20 hrs 2mCi 90Sr With heating: 325 hrs 2mCi 90Sr

½ year ½ year

Preventing Treatments: 1) Long term flushing 2) Heating of the modules 3) Lowering the gas flow 4) Adding O2 to the counting

gas

2) Heating (Lab):

1) Flushing:

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Recovery Treatment

2nd HV training

1st HV training

3rd HV training R

elati

ve G

ain

Irradiation Time (hours)

Before HV training

After HV training

Trained half

Non-trained half

HV training (24 hours, 1900 V, G~106) Dark current ~10 m A/wire Wire inspection promising:

• no carbon deposits despite large currents

Outer Tracker

Outlook OTDetector installed and alignedElectronics production being finalizedCommissioning underway Irradiation resistance studies ongoing:

Detectors being flushed and heated Investigating HV training procedure Further testing of ``TraBond module´´

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Software: Reconstruction, Trigger & Physics

NIKHEF provides Trigger deputy project leader(HLT implementation)

Nikhef Contributions:• Kalman Filter track fitting• Software Alignment: Framework, Geometry, Kalman filter implementation • HLT implementation• DaVinci and LoKi physics frameworks

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Display of LHCb simulated event

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Key measurements – NIKHEF group

• CKM Metrology: 1. Amix: Bs → Ds p Dms ACP: Bs

→ Ds K -g fs

2. ACP: Bs → J/ y f fs

• Rare Decays:1. Br: B(s)→mm

2. Afb: B0 →K*mm , b →s mm

Looking for effects of new physics in the flavour sector:

2B bs

sb

“Box”

Well matched to our activities:i. VeLo and OT constructionii. Track reconstruction

“Penguin”b s

1B

4 “teams”: each with 1-2 staff, 1 postdoc, 2-3 students

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Dimuon mass resolution:Track c2/dof:

Kalman Track Fitting and Alignment Reconstruct tracks including

multiple scattering. Tracking in realistic (misaligned)

geometry. Simultaneous detector element

alignment fit and trackfit z

J/ y peak— UnalignedO Aligned∆ Default

— UnalignedO Aligned∆ Default

Example: Bs→ J/ y f . Simultaneous likelihood analysis

in time, mass, angular distribution domains

time

mass

cos qtr

cosqf

ftr

signalbackg

sum

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Theses b-physics• Theses on LHCb:

– (2001) N. Zaitsev Pile-up and Bs→J/yf– (2002) R. v.d. Eijk OT and tracking– (2003) R. Hierck Tracking and Bs→DsK/p– (2004) N. v. Bakel Velo and Bs mixing– (2005) S. Klous Velo and Bs →J/ y f– (2005) J. v. Tilburg Tracking and Bs→Ds K/ p– (2006) B. Hommels Tracking and Trigger– (2007) J.Nardulli Reconstruction of two body B decays in LHCb

• Theses on Hera-B:– (2002) M. Bruinsma J/y in pA– (2002) W. Hulsbergen Track reconstruction– (2003) M. Mevius B cross-section– (2005) H. Wahlberg B cross-section– (2006) A. Sbrizzi B X-section & pentaquark

• Thesis on Babar:– (2006) M.Baak CKM angle gamma

17-4-2008

Nikhef-evaluation 336-sept-2007

The B-Team

The “technical” Beauties! (the real backbone)

The mad young geniuses:The Muscles:

Those who love it when a plan comes together (the Planners):

The B-team

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Summary• Velo

– Cooling, vacuum, motion control are “ready”• The devil is in the (unforseen) detail

– PileUp detectors installed, trigger implementation requires effort– New RF-boxes being produced

• Outer Tracker– Detector installed and aligned– Electronics installation under time pressure– Irradiation studies ongoing with high priority

• Software– Reconstruction framework ready– Tracking fitting and Alignment algorithms tested– Selection and physics algorithms being developed

• Upgrade– Investigating contributions:

• Better RF boxes• Velo module replacement• OT operation under high luminosity• 40 MHz readout electronics17-4-2008

The End

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The Scientific Team (NIKHEF, VU)• Scientific Staff: (~9 FTE)

– Bauer (0,5 OT), v Beuzekom (0.8, Velo), v/d Brand (0.5, Velo), Bulten (0.5,Phys), Hulsbergen (1, Reco), Jans (1, Velo), Ketel (0.5, OT/Velo), Merk (1), Pellegrino (1,OT), Raven (1,Phys), Tuning (1, OT,Phys), de Vries (0.8, Velo), Wiggers (0.7, PileUp/Upgrade)

• Post-docs:– Belyaev (Phys), Kazu (Velo/Phys), Palacios (Reco), Serra (Phys), Terrier (OT) ,

Van Lysebetten (Velo)

• Graduate Students:– Amoraal (Reco), Bos (Reco), Jansen (OT), M’charek (OT/Phys), Mous (Velo),

Papadelis (Velo), du Pree (Phys), Simioni (OT/Phys), Snippe (Velo), Snoek (Babar), Storaci (OT ), Ybeles-Smit (Phys)

• Master Students:– Aaij (Reco), Hooft v. Huysduynen (Phys)

The group

Staff Members 12 people (~9 FTE) : 2(30+), 4(40+), 5(50+), 1(60+)

Postdocs 3 FOM-Nikhef, 1 FOM-PR, 1 NWO-Vidi

Technical Staff 7 (3 OT+4 Velo) Mechanics Engineers, 4 (2 OT+2 Velo) Mechanics

Workshop, 8 (3 OT+5 Velo) Electronics, 1 Computing

Graduate Students 6 FOM-Nikhef, 1 FOM-BUW, 1 VU, 1 NWO-Vidi

2 Master students

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LHCb experiment in the cavern

31-3-2008 38

Shielding wall(against radiation)

Electronics + CPU farm

Offset interaction point (to make best use of existing cavern)

Detectors can be moved away from beam-line for access

b-b in LHCb

31-3-2008 39

LHCb event rate: 40 MHz1 in 160 is a b-b event

Background SupressionFlavour taggingDecay time measurement

• vertices and momenta (mass) reconstruction • effective particle identification (π, К, μ, е, γ)• triggers

qb

qb