LHCb Status Report:LHCb Status Report: B-Physics with Tracking

SAC Review MeetingApril 20, 2007Marcel Merk

for the B-physics group

Contents:• Outer Tracker • Vertex Locator• Software

2

LHCb detector

10 mrad

b

b

250 mrad

3

Silicon strip detector Reconstruct primary and

secondary vertices Tracking, use R-Phi geometry Used in L1 trigger Pile-Up Trigger in L0

The VErtex LOcator in LHCb

4

Straw tube detector Momentum determination with

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

The Outer Tracker in LHCb

5

The Experiment

VeloOT

6

Outer Tracker - Collaboration

J. Amoraal, R. Arink, H. Band, Th.S. Bauer, A. Berkien, L. Ceelie,

G. Fanizzi, F. Jansen, B. M’charek, A. Pellegrino, O. v. Petten,

T. du Pree, J. Rovekamp, F. Schimmel, H. Schuijlenburg,

E. Simioni, T. Sluijk, J. Spelt, H.Terrier, N. Tuning, A. Zwart

The NIKHEF OT group:

Dortmund, Heidelberg, Warsaw, Cracow, Bejing, VU, Nikhef:

NIKHEF provides OT project leader

Nikhef Activities:•Mass production: mechanics & electronics•Infrastructure: frames and support bridge•Installation & quality Assurance•Irradiation studies

7

The Outer Tracker

C-frame OT

Bridge

Table & Cable Trays

Modules

8

OT Modules and Performance

One large module: 34 x 490 cm2

4 x 64 = 256 channels

Resolution: σ 200 µm

Plateau Efficiency: ε 100%

9

Detector Installation - completed

Front-End Boxes

LV,HV, ECS/TFC..

Cooling and Gas

Detector Modules

module

Δz

[mm

]

Mechanical installation precision:

z-coordinate: deviation within 1 mm

T2-Q02-XUX-layer

10

Electronics

First C-frame equipped with FE boxes

HV board: 900 of 2000 tested and assembled Problem with alignment holes

ASDBLR amplifier board: All 4000 boards produced

OTIS TDC board: Total 2000 boards needed Bonding completed! (Major task..)

GOL AUX board: Production & Test completed

11

Quality Assurance

Tests C-frames LV, HV, Data Fibers, Gas

Tests detector modules: Gast tightness, dark currents,

signals R.A. sources

Tests Front End Amplifier threshold uniformities Time resolution

Commissioning Noise measurement Testpulse tests:

• Linearity, stability, resolution, uniformity

12

Module 61

Channel nr.

Pu

lse

he

igh

t (m

V)

Tested in the pit in the C cage

4 “dead” wires out of 6867 tested

Example QA : Straw Response to 55Fe

6 April 2006 13

Outer Tracker Irradiation Studies

Cha

nnel

Pos (cm)

Gain loss seen in production modules Damage upstream the gas flow

Damage only in low intensity region!

Electron microscope: isolating carbon layer

6 April 2006 14

Outer Tracker Irradiation Studies

Cha

nnel

Pos (cm)

Suspect out-gassing effect: Flushing of all modules started Warming of modules to force outgassing HV processing cures and part. Prevents

Gain loss seen in production modules Damage upstream the gas flow

Damage only in low intensity region!

Electron microscope: isolating carbon layer

Flushing

R

el g

ain

Flush Time (days)

2nd HV training

1st HV training

3rd HV training R

elat

ive

Gai

n

Irradiation Time (hours)

15

Velo - Collaboration

The NIKHEF Velo group:

NIKHEF provides Velo deputy projectleader

Nikhef Activities:Mechanics + RF Motion ControlVacuum control CO2 CoolingPile-Up trigger

Heidelberg, MPI, Liverpool, Glasgow, CERN, Lausanne, Syracuse, VU, Nikhef

M. Beuzekom, J. v/d Brand, M. Doets, P. de Groen, E. Jans,

L. Jansen, T. Ketel, A. Keune, M. Kraan, F. Mul, B. Munneke,

A. Papadelis, E. Roeland, F. Schimmel, A. Van Lysebetten,

B. Verlaat, T. Versloot, H. de Vries, L. Wiggers

16

VErtex LOcator

Silicon sensors

Vacuum vessel

  rf-box

rectangular bellows

exit window

wake field suppressor

~1 m kaptons

The Vertex Locator

17

VELO Detector half

18

The Detector Vacuum box (“RF Box”)

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

• super plastic pressing of 300 m Al foil with hot gas• welding into a vacuum tight box

30 mm

19

The Detector Vacuum box (“RF-box”)

Leak rate between beam and detector volumes determined to be : 2.4x10-5 mbar.l/s @ 1.6 mbar He Saturation NEG coating during installation Other solution considered for 2009 run

p < 5 mbar at all times!

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Vacuum

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

-6

-4

-2

0

2

4

6

11:16 11:31 11:45 12:00 12:14 12:28

0

200

400

600

800

1000

1200

p[mbar]

10

time

pbeam-pdet.

[mbar]

0

400

800

1200

0

4

-4

21

How the beam sees the Velo

22

Positioning the Detector in the beam: Motion Control

parking position

closed position

motion control implemented in a PLC. software and hardware limits. reproducibility < 10 m UPS system 3 d.o.f.: XR, XL and Y

Allowed regions:-5.0 < X < 29.0 mm for -1.0 < Y < 1.0 mm

-4.7 < Y < 4.7 mm for X < 5.0 mm

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015 -1530 -30[mm]

rf-foil rf-foil

VELO open

0

.

half-open VELO tracking

LHC-beams

crossing

VELO closed

15

-15

30

-30

-45

45

[mm]

24

Cooling system and cooling plant

CO2 part ready

Next steps: Cabling, PLC control, insulation, testing

Delivery at CERN by June

Flexible in and outlet lines

Capillary and

T-Sensor channel

Cooling blocks

PT100 cables

PT100 Interface board

Vapor outlet

Liquid inlet

Cooling vacuum

feed trough

25

Pile-Up trigger

4 Upstream modules with R-sensors Uses digital readout of Beetle chips vetoes BXs with multiple PV’s

4PU-hybrids

8 opticalTx-boards

4 vertexprocessing

boards

1 outputboard

L0DU

125 Gb/s

und

er

con

stru

ctio

n

4PU-hybrids

8 opticalTx-boards

4 vertexprocessing

boards

1 outputboard

L0DU

125 Gb/s

und

er

con

stru

ctio

n

26

Software - Overview

J. Amoraal, Th. Bauer, E. Bos, H.J. Bulten, S. Cohen, L. Hooft van

Huysduyn, B. M’charek, M. Merk, J. Nardulli, A. Papadelis, G. Raven,

T. du Pree, N. Tuning, P Vankov, G. Ybeles Smit,

The NIKHEF Software group:

NIKHEF has convenorship of:

- Proper time and mixing group- Track fitting group

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Physics Motivation

CKM Metrology:

1. Amix: Bs → Ds ms

ACP: Bs → Ds Ks

2. ACP: Bs → J/s

Rare Decays:

1. Br: B(s)→2. Afb: B0 →K* , b →s

Looking for effects of new physics in the flavour sector:

2B bs

sb

“Box”

These subjects exploit LHCb advantages over otherexperiments

Well matched to our activities:i. OT constructionii. VELO constructioniii. Track reconstruction

“Penguin”b s

1B

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

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Result of track finding

Typical event display:Red = measurements (hits)

Blue = all reconstructed tracks

Efficiency vs p : Ghost rate vs pT :

Eff = 94% (p > 10 GeV)

Ghost rate = 3%(for pT > 0.5 GeV)

VELO

TT

T1 T2T3On average:

26 long tracks11 upstream tracks4 downstream tracks5 T tracks26 VELO tracks

2050 hits assigned to a long track: 98.7% correctly assigned

Ghosts:Ghosts:Negligible effect onNegligible effect onb decay reconstructionb decay reconstruction

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Kalman Track Fit

Reconstruct tracks including multiple scattering.

Main advantage: correct covariance matrix for track parameters.

Implemented tracking in misaligned geometry.

z

Impact parameter pull distribution:

= 1.0

rec truer r

r

Momentum pull distribution:

= 1.2

rec truep p

p

30

Impact Parameter and Momentum Resolution

IP= 14 + 35 /pT

Impact parameter resolution parameter resolution

→ 1/pt (1/GeV)

1/pT spectrum B tracks

p/p = 0.35% – 0.55%

p spectrum B tracks

Momentum resolution

→ Momentum (GeV)

31

Mass and Lifetime resolution

BsDs proper time resolution

t ~ 40 fs

Example:Bs->Ds K/

Ds

Bs K

K

,K

47 m 144 m

440 m

Mass and lifetime resolutions Are typically a factor 2-3 better than ATLAS/CMS

Mass resolution: ~14 MeV Proper time resolution: ~40 fs

32

Theses b-physics

Theses on LHCb: (2001) N. Zaitsev Pile-up and Bs→J (2002) R. v.d. Eijk OT and tracking (2003) R. Hierck Tracking and Bs→DsK/ (2004) N. v. Bakel Velo and Bs mixing (2005) S. Klous Velo and Bs →J/ (2005) J. v. Tilburg Tracking and Bs→Ds K/ (2006) B. Hommels Tracking and Trigger

»

Theses on Hera-B: (2002) M. Bruinsma J/ 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

33

Summary

Outer Tracker Detector installed Cabling ready Front end being tested and installed (tight schedule!) Commissioning ongoing Irradiation studies ongoing with high priority

Velo Vacuum vessel installed Vacuum control commissioned: leak detected in RF boxes Motion control commissioned Cooling infrastructure being installed in summer

Software Reconstruction framework ready Tracking algorithms being finalized Alignment algorithms being implemented Looking forward to data (hopefully already in 2007…)