BaBar Drift Chamber performance Markus Cristinziani Stanford Linear - - PowerPoint PPT Presentation

Performance Background Upgrade HiLumi Extra

BaBar Drift Chamber performance

Markus Cristinziani

Stanford Linear Accelerator Center

Markus Cristinziani BaBar Drift Chamber performance 0 / 28

Performance Background Upgrade HiLumi Extra

Outline

1

BaBar Drift Chamber performance

2

Backgrounds

3

Electronics upgrade

4

Higher luminosities

5

Additional material for discussion

Markus Cristinziani BaBar Drift Chamber performance 0 / 28

Performance Background Upgrade HiLumi Extra

Outline

1

BaBar Drift Chamber performance

2

Backgrounds

3

Electronics upgrade

4

Higher luminosities

5

Additional material for discussion

Markus Cristinziani BaBar Drift Chamber performance 0 / 28

Performance Background Upgrade HiLumi Extra

Drift Chamber design and operation

Main tracking device in BaBar surrounding SVT 2.8m length, 1.6m diameter, 7104 sense wires 40 axial and stereo layers of 1-2cm hex cells Gas: 80:20 He:C4H10, 4000 ppm H2O vapor Operating voltage: 1930V

IP

1618 469 236 324 68 1015 1749

551 973 17.19 202 35

Markus Cristinziani BaBar Drift Chamber performance 1 / 28

Performance Background Upgrade HiLumi Extra

Reconstruction

Single hit resolution 125 µm Momentum resolution, pT : 0.45% + 0.15% pT /( GeV /c) Tracking efficiency : >95% matching with SVT tracks dE/dx resolution ≈ 7.5%

Markus Cristinziani BaBar Drift Chamber performance 2 / 28

Performance Background Upgrade HiLumi Extra

Particle identification

p<0.6 GeV/c

Drift Chamber K/π Separation

50

π K

0.6<p<0.8

100

π K

0.8<p<1

100

π K

DCH dE/dx - dE/dx(K)

(arb. units) p>1 GeV/c

1000

• 600
• 400
• 200

200

π K Drift Chamber K/π Separation

BABAR

Good K/π separation up to ≈ 700 MeV /c Provides confirmation of DIRC information Additional coverage outside DIRC acceptance

Markus Cristinziani BaBar Drift Chamber performance 3 / 28

Performance Background Upgrade HiLumi Extra

Tracking

Mass difference as a function of reconstructed distance from IP K0

S → π+ π−

Λ → pπ−

)

2 Vtx

+Y

2 Vtx

(X √ Decay Radius )

2

M (GeV/c ∆

• 0.001
• 0.0005

0.0005 0.001 10 20 30 40 50

Fits with DCH only are comparable to full tracking “Jumps” are due to material scattering uncertainty

go to pseudoefficiency plot Markus Cristinziani BaBar Drift Chamber performance 4 / 28

Performance Background Upgrade HiLumi Extra

Outline

1

BaBar Drift Chamber performance

2

Backgrounds

3

Electronics upgrade

4

Higher luminosities

5

Additional material for discussion

Markus Cristinziani BaBar Drift Chamber performance 4 / 28

Performance Background Upgrade HiLumi Extra

Background characterization – Motivation

PEP-II plans to increase luminosity to 2 × 1034 by 2007 Increasing luminosity means

aging

go to aging

increased read-out time and deadtime larger occupancy potentially affecting tracking

A set of background characterization runs were taken to study BaBar behavior as a function of beam currents and luminosity Used to extrapolate to future luminosities

Markus Cristinziani BaBar Drift Chamber performance 5 / 28

Performance Background Upgrade HiLumi Extra

Background characterization – Method

49 short runs were recorded during 16 hours in January 2004 with varying beam currents and configurations Quantities of interest (Drift Chamber current, occupancy and read-out time) are parametrized with a functional form Bkg = A + B ILER + C I2

LER + D IHER + E I2 HER + F L

where [ILER] = [IHER] = A and [L] = 1033 no LER*HER term as no 2-beam, non-collision data taken beam-beam interaction and trickle injection is added linearly in the extrapolations fitting is performed in a 3-step approach

fit pedestal runs and extract A fit single-beam runs after pedestal subraction (→ B-E) fit luminosity runs after single-beam subtraction (→ F)

1-step - simultaneous fit to all parameters as cross-check

Markus Cristinziani BaBar Drift Chamber performance 6 / 28

Performance Background Upgrade HiLumi Extra

Background characterization – Result

FCN A B C D E F No beam pedestal 56 0.606 +- 0.033 —0.0— —0.0— —0.0— —0.0— —0.0— Single beam LER 227 —0.606— 0.21 +- 0.07

• 0.03 +- 0.05

—0.0— —0.0— —0.0— Single beam HER 117 —0.606— —0.0— —0.0— 4.76 +- 0.21

• 0.96 +- 0.25

—0.0— No quadratic terms Single beam LER 227 —0.606— 0.166 +- 0.018 —0.— —0.0— —0.0— —0.0— Single beam HER 131 —0.606— —0.0— —0.0— 3.97 +- 0.06 —0.— —0.0— Lumi HER 2/3, LER scan 36 —0.606— —0.166— —0.00— —3.966— —0.00— 0.460 +- 0.015 Lumi HER max, LER scan 47 —0.606— —0.166— —0.00— —3.966— —0.00— 0.372 +- 0.012 Lumi LER 2/3, HER scan 139 —0.606— —0.166— —0.00— —3.966— —0.00— 0.393 +- 0.015 Lumi LER max, HER scan 116 —0.606— —0.166— —0.00— —3.966— —0.00— 0.525 +- 0.011 Lumi trickle, HER scan 118 —0.606— —0.166— —0.00— —3.966— —0.00— 0.555 +- 0.015 All good Lumi points 348 —0.606— —0.166— —0.00— —3.966— —0.00— 0.420 +- 0.007 Preferred result 0.61 0.17 0. 3.97 0. 0.42

Occupancy(%) = 0.61 + 0.17 ILER + 3.97 IHER + 0.42 L +0.21 ILER (beam − beam)+0.03 L (trickle inj.)

LER current (mA) 500 1000 1500 2000 Occupancy (%) 0.5 1 1.5 2 2.5

Entries 2559 Mean x 1067 Mean y 0.7881 RMS x 463 RMS y 0.3099 1 2558

1 10

Entries 2559 Mean x 1067 Mean y 0.7881 RMS x 463 RMS y 0.3099 1 2558

Single beam LER HER current (mA) 500 1000 Occupancy (%) 1 2 3 4 5 6

Entries 2301 Mean x 588.1 Mean y 2.98 RMS x 318.9 RMS y 1.193 2301

1 10

Entries 2301 Mean x 588.1 Mean y 2.98 RMS x 318.9 RMS y 1.193 2301

Single beam HER

Luminosity (1e33) 2000 4000 6000 Occupancy - Single Beam contribution (%)

• 1

1 2 3 4 5 6

Entries 1865 Mean x 3523 Mean y 2.092 RMS x 1905 RMS y 0.9662 1 1864

1 10

Entries 1865 Mean x 3523 Mean y 2.092 RMS x 1905 RMS y 0.9662 1 1864

Lumi trickle, HER scan

Markus Cristinziani BaBar Drift Chamber performance 7 / 28

Performance Background Upgrade HiLumi Extra

Babar-Belle Backgrounds Task Force

Goal is to understand differences and commonalities in background patterns For DCH and CDC similar currents but different occupancies are observed

go to DCH and CDC comparison

Geographical background distributions

• 10

10

• 15
• 10
• 5

5 10 15 5 6 7 8 9 10 11 12 13 14

I O T B

Average Occupancy (%) -- typical run

LER only HER only Luminosity

SuperLayer Hits/wire (a.u.)

0.02 0.04 0.06 0.08 0.1 0.12 0.14 0.16 1 2 3 4 5 6 7 8 9 10

LER only HER only Luminosity

phi

0.01 0.02 0.03 0.04 0.05 0.06 0.07 0.08 0.09 1 2 3 4 5 6

Markus Cristinziani BaBar Drift Chamber performance 8 / 28

Performance Background Upgrade HiLumi Extra

Outline

1

BaBar Drift Chamber performance

2

Backgrounds

3

Electronics upgrade

4

Higher luminosities

5

Additional material for discussion

Markus Cristinziani BaBar Drift Chamber performance 8 / 28

Performance Background Upgrade HiLumi Extra

Motivation

During poor background conditions the dead time is driven by DCH Cause: Serialization and shipping of data from the front-end to the ROM Increased luminosity L ∼ 9 × 1033 Increased L1 rate ∼ 2 kHz Problem: Dead time was noticeable in Run 4 Would have been significant in Run 5 with no intervention

Hour of March 31 Deadtime (%)

DCH GLT SVT EMT Other

2 4 2 2.1 2.2 2.3 2.4 2.5

Markus Cristinziani BaBar Drift Chamber performance 9 / 28

Performance Background Upgrade HiLumi Extra

Read-out time extrapolations

Predictions for future PEP beam configurations

100 200 300 400 2004 2005 2006 2007 2008

trickle beam-beam Lumi LER HER constant

30% deadtime Year DCH Read-out time (µs)

Extrapolations Dead time would soon become a serious issue e.g. 30% at 5 kHz in 2007 PEP parameters

year ILER IHER L(1034) 2004 2.45A 1.55A 0.9 2005 3.1A 1.7A 1.1 2006 3.6A 1.8A 1.3 2007 4.0A 2.0A 2.0 2008 4.5A 2.2A 2.1

Short-term solution: ship less raw data! →

Markus Cristinziani BaBar Drift Chamber performance 10 / 28

Performance Background Upgrade HiLumi Extra

Implementation: Waveform decimation

20 40 60 80 100 120 5 10 15 20 25 30 TDC

Waveform byte FADC counts 32 samples of FADC values with bilinear packing; time information

• f TDC hits override ADC value

Algorithm: out of a pair keep the TDC hit or ship the second sample This preserves all TDC hits and reduces waveform to 16 bytes Expand decimated waveform to

• riginal size interpolating in the

ROM after the bottleneck

Markus Cristinziani BaBar Drift Chamber performance 11 / 28

Performance Background Upgrade HiLumi Extra

Implementation: Waveform decimation

20 40 60 80 100 120 5 10 15 20 25 30 TDC TDC

Waveform byte FADC counts 32 samples of FADC values with bilinear packing; time information

• f TDC hits override ADC value

Algorithm: out of a pair keep the TDC hit or ship the second sample This preserves all TDC hits and reduces waveform to 16 bytes Expand decimated waveform to

• riginal size interpolating in the

ROM after the bottleneck

Markus Cristinziani BaBar Drift Chamber performance 11 / 28

Performance Background Upgrade HiLumi Extra

Implementation: Waveform decimation

20 40 60 80 100 120 2 4 6 8 10 12 14 16 TDC

Waveform byte FADC counts 32 samples of FADC values with bilinear packing; time information

• f TDC hits override ADC value

Algorithm: out of a pair keep the TDC hit or ship the second sample This preserves all TDC hits and reduces waveform to 16 bytes Expand decimated waveform to

• riginal size interpolating in the

ROM after the bottleneck

Markus Cristinziani BaBar Drift Chamber performance 11 / 28

Performance Background Upgrade HiLumi Extra

Implementation: Waveform decimation

20 40 60 80 100 120 5 10 15 20 25 30 TDC

Waveform byte FADC counts 32 samples of FADC values with bilinear packing; time information

• f TDC hits override ADC value

Algorithm: out of a pair keep the TDC hit or ship the second sample This preserves all TDC hits and reduces waveform to 16 bytes Expand decimated waveform to

• riginal size interpolating in the

ROM after the bottleneck

Markus Cristinziani BaBar Drift Chamber performance 11 / 28

Performance Background Upgrade HiLumi Extra

Hardware implementation

Read-out interface board of a DCH front end assembly Firmware Only a firmware change in PROM which drives the slave FPGA Status Burnt and validated before shutdown Fully implemented with uploadable software Validated with Run4 data and cosmics

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Performance Background Upgrade HiLumi Extra

Emulation with data

We have the ability to ship raw waveforms together with data End of March 2004 ∼ 30 runs were taken in this mode Applied decimation algorithm to 14 of these runs Evaluate the effect of waveform decimation at the level of Single digis

go to details

Track-by-track comparison (1 run)

go to details

dE/dx distributions

go to details

Physics from online monitoring (3.5 runs)

go to details Markus Cristinziani BaBar Drift Chamber performance 13 / 28

Performance Background Upgrade HiLumi Extra

Example physics check

Simple Analysis not available in standard monitoring Look at m(D∗) − m(D0) in D∗+ → D0(K−π+)π+ Channel interesting for tracking (slow π) and PID (K/π separation)

50 100 150 200 250 300 140 150 160 170 S/B3σ = 1.029 ± 0.08

769.6 / 747.6

7777 entries m(D*) - m(D0) [MeV] Events Original 32 bytes DCH waveforms 50 100 150 200 250 300 140 150 160 170 S/B3σ = 1.019 ± 0.08

782.9 / 768.6

7759 entries m(D*) - m(D0) [MeV] Events Modified 16 bytes DCH waveforms

Yields and S/B ratio are unchanged within statistical errors

Markus Cristinziani BaBar Drift Chamber performance 14 / 28

Performance Background Upgrade HiLumi Extra

Performance comparison on cosmics runs

Looked at actual data (cosmics) Compare before (black) and after (red) electronics change Global gain difference due to testing of different gas composition After calibration (green) no difference in dE/dx

Momentum (GeV) 2 4 6 8 10 12 14 de/dx 100 200 300 400 500 600 700 800

de/dx December de/dx July(normalized) de/dx July

dE/dx vs P Dip Angle (Rads)

• 1
• 0.5

0.5 1 de/dx 100 200 300 400 500 600 700 800

de/dx December de/dx July(normalized) de/dx July

dE/dx vs Dip

The present fix buys us some precious time at a low cost and solves the dead time problem on the short time

go to additional plots Markus Cristinziani BaBar Drift Chamber performance 15 / 28

Performance Background Upgrade HiLumi Extra

Full upgrade

Redesign the front-end board to perform feature extraction directly Installed a “Phase II” board on the detector in December 2004

Can switch between “old” and “new” configuration, uploading software into the FPGA Waiting for beams to ensure radiation tolerance

Pre-production board testing is being finalized New boards will be installed during short accesses to the IR

)

• 1

s

• 2

cm

33

Luminosity (x 10

20 40

Deadtime (%)

20 40 60 80 100

Nominal Background - 2004 projection Present DAQ With Decimation DAQ upgrade

2003 2004 2005 2006 2007-2010

Markus Cristinziani BaBar Drift Chamber performance 16 / 28

Performance Background Upgrade HiLumi Extra

Outline

1

BaBar Drift Chamber performance

2

Backgrounds

3

Electronics upgrade

4

Higher luminosities

5

Additional material for discussion

Markus Cristinziani BaBar Drift Chamber performance 16 / 28

Performance Background Upgrade HiLumi Extra

Tracking at high luminosity

Mix Monte Carlo B → D(∗)D(∗) with real random-trigger data Multiple triggers overlaid to match luminosity extrapolations Evaluate physics quality relative to current performance

Compared to design 2 × 1034 4 × 1034 4 × 1034 3 × 1033 L (3× bkg) (5× bkg) (10× bkg) Tracking eff. (%) 98.6 ± 0.1 ± 0.7 97.4 ± 0.1 ± 1.0 Momentum σ(p)/p = 4.7 × 10−3 +4.2 × 10−5 +5.5 × 10−5 D0 → K+π− (%) 96.0 ± 0.5 95.5 ± 0.5 80 ± 3 D0 Mass σ = 6.5 ± 0.2 MeV /c2 6.5 ± 0.2 6.4 ± 0.2 7.0 ± 0.3 D∗ → D0π (%) 84.4 ± 1.1 75.0 ± 1.3 25 ± 2 D∗ Mass σ = 0.80 ± 0.03 MeV /c2 0.97 ± 0.04 1.50 ± 0.08 3.2 ± 0.8 Markus Cristinziani BaBar Drift Chamber performance 17 / 28

Performance Background Upgrade HiLumi Extra

Extrapolation to much higher luminosity

How would the Drift Chamber perform in an 1036 environment? Only a rough guess can be made with these assumptions: Backgrounds scale according to January parameterization Finer segmentation, e.g. cell size down to 1/8th Luminosity term might be reduced by a factor of 5

5 10 15 20 8 200 700 1000

8x cells

Lumi HER LER 20% Lumi HER LER

BABAR

Luminosity [1033] Occupancy [%]

Markus Cristinziani BaBar Drift Chamber performance 18 / 28

Performance Background Upgrade HiLumi Extra

Conclusion

BaBar Drift Chamber is stable and performing as designed – since 5 years After initial problems, aging is well understood and under control Deadtime bottleneck solved with electronics upgrade in two phases With the full upgrade the chamber is well suited for data taking until the end of the BaBar lifetime In the present configuration occupancy will soon become prohibitive with increasing luminosities

Markus Cristinziani BaBar Drift Chamber performance 19 / 28

Performance Background Upgrade HiLumi Extra

Outline

1

BaBar Drift Chamber performance

2

Backgrounds

3

Electronics upgrade

4

Higher luminosities

5

Additional material for discussion

Markus Cristinziani BaBar Drift Chamber performance 19 / 28

Performance Background Upgrade HiLumi Extra

Performance degradation in Run4

We observe ∼ 5% less reconstructed B per fb−1 Significant changes in running mode (injection → trickle) Average background level is higher Key point is that this effect is modeled correctly in Monte Carlo The effect goes inversely with purity of the signal DCH pseudo- efficiency plot for Run4 data Efficiency for Drift Chamber, normalized to SVT tracks

return to talk Markus Cristinziani BaBar Drift Chamber performance – Extra material 20 / 28

Performance Background Upgrade HiLumi Extra

Aging and gain variation

Continously monitoring accumulated charge per unit wire length

DCH Dose Since Startup (May 1999 - Present)

5 10 15 5 10 15 2000 5 10 15 2001 5 10 15 2002 5 10 15 2003 5 10 15 2004

Accumulated Charge (mC/cm)

Total charge 16.9 mC/cm in five years

Accumulated Charge (mC/cm) Corrected Gain

DCH Gain Since Startup (May 1999 - Present)

0.4 0.6 0.8 1 1.2 5 10 15 Aging rate: -0.639± 0.011 %/(mC/cm) over 16.86 mC/cm

After “accident” (cured adding water vapor), smooth decrease with time Long-term studies of aging and remediation accumulated several times BaBar lifetime charge

return to Background characterization Markus Cristinziani BaBar Drift Chamber performance – Extra material 21 / 28

Performance Background Upgrade HiLumi Extra

Babar-Belle Backgrounds Task Force

CDC-DCH Belle BABA R BABA R 1034 same Lumi same beams total current (µA) 1000 1050 620 fraction due to const 8 0% 0% fraction due to LER 65% 5% 5% fraction due to HER 27% 37% 45% fraction due to lumi 0% 57% 49%

• ccupancy

1⋆% 9% 6%

Currents Comparison is approximate since absolute gain measurement is uncertain

40000 in 1998 for BaBar 20000 in 1994 for Belle (×2-3)

Occupancy Belle measures hit rate (discriminator+scaler) BaBar uses random triggers, multi-hit electronics, a waveform quality cut and integrates over 2µsec

return to talk Markus Cristinziani BaBar Drift Chamber performance – Extra material 22 / 28

Performance Background Upgrade HiLumi Extra

Effect on digis

Comparison at the single DCH digi level Charge resolution degradation for single digis is ∼ 6% A charge and TDC dependent correction is applied but is nearly irrelevant 0.6% originally “good” digis do not pass the Q > 50 cut (QMOD - Q)/Q Occurence (%)

µ = 0.03% σ = 5.6% Q > 50 0.6% 5 10 15 20 25 30

• 1
• 0.5

0.5 1

Expected new dE/dx resolution (for Bhabha’s) (9 ⊕ 6/ √ 35)% = 9.05%

return to talk Markus Cristinziani BaBar Drift Chamber performance – Extra material 23 / 28

Performance Background Upgrade HiLumi Extra

Track-by-track comparison

Method: Try n2 combinations and sort track pairs by ∆φ Match and remove pairs if ∆φ < 0.01 Similarly for # of same hits > 5 on remaining track pairs Statistics on one run : 2.125 Mtracks Out of 1000 tracks: 713 tracks are identical 281 are matched by φ and hits 6 are lost 7 new are found with compatible distributions lost tracks : low hit multiplicities, high bckgnd, ghosts, loopers, ...

) φ ∆ (

10

Log

• 10

Fraction 0.5 1

φ ∆ Track match in Same Event Event Mix

Hits 50 Fraction 0.05 0.1 0.15

Matched Missed Found

return to talk Markus Cristinziani BaBar Drift Chamber performance – Extra material 24 / 28

Performance Background Upgrade HiLumi Extra

Effect on dE/dx

Reconstructed 3.5 runs comparing old and new algorithm Yields and distributions of electron and protons are unaffected Carefully scanned tens of monitoring plots

RUN 0 - DCHOPRDEDXMON/ELECTRONS - 1

Tracks dE/dx Tracks dE/dx

Nratio: 1.00 µratio: 1.00 σ⊕: 7.709

22428 ⇒ 22459 665.796 ⇒ 663.019 60.7375 ⇒ 61.2248 Original Modified WF

500 1000 1500 2000 2500 3000 3500 200 400 600 800 1000

RUN 0 - DCHOPRDEDXMON/ELECTRONS - 7

Tracks dE/dx resolution Tracks dE/dx resolution

Nratio: 1.00 µratio: -16.36 σ⊕: 0.009

22428 ⇒ 22459 0.000 ⇒ -0.004 0.0900 ⇒ 0.0905 Original Modified WF

250 500 750 1000 1250 1500 1750 2000 2250

• 0.4
• 0.2

0.2 0.4

RUN 0 - DCHOPRDEDXMON/PROTONS - 7

Tracks dE/dx resolution Tracks dE/dx resolution

Nratio: 1.02 µratio: 1.13 σ⊕: 0.008

14623 ⇒ 14908

• 0.013 ⇒ -0.015

0.0895 ⇒ 0.0898 Original Modified WF

200 400 600 800 1000 1200 1400

• 0.4
• 0.2

0.2 0.4

Resolution is marginally degraded, as expected from single digis

return to talk Markus Cristinziani BaBar Drift Chamber performance – Extra material 25 / 28

Performance Background Upgrade HiLumi Extra

Effect on physics

Example of monitoring plots available in standard production All tracks

RUN 0 - DCHOPRMON/ALLTRACKS - 1

Number of tracks Number of tracks

Nratio: 1.00 µratio: 1.01 σ⊕: 0.306

97654 ⇒ 97663 3.488 ⇒ 3.520 2.5823 ⇒ 2.6003 Original Modified WF 5000 10000 15000 20000 25000 30000 35000 2.5 5 7.5 10

Kaon selection

RUN 0 - PHYSMONMODULE - 5

Phi Mass Phi Mass

Nratio: 1.00 µratio: 1.00 σ⊕: 0.000

29956 ⇒ 29836 1.019 ⇒ 1.019 0.0136 ⇒ 0.0136 Original Modified WF 200 400 600 800 1000 1 1.01 1.02 1.03 1.04 return to talk Markus Cristinziani BaBar Drift Chamber performance – Extra material 26 / 28

Performance Background Upgrade HiLumi Extra

Performance comparison on cosmics runs

dE/dx 200 400 600 800 1000 1200 1400 Counts 100 200 300 400 500 600

dE/dx July Cosmics Run 50437 dE/dx December Cosmics Run 51966

dE/dx dE/dx 200 400 600 800 1000 1200 1400 Counts 100 200 300 400 500 600

dE/dx July Cosmics dE/dx December Cosmics dE/dx July(normalized)

dE/dx

Momentum (GeV) 2 4 6 8 10 12 14 50 100 150 200 250 300 350 400 dE/dx December - dE/dx July (normalized) Vs P Dip Angle (Rads)

• 1
• 0.5

0.5 1

• 600
• 400
• 200

200 400 600 dE/dx December - dE/dx July (normalized) Vs Dip Phi (Degrees)

• 150
• 100
• 50

50 100 150 100 200 300 400 500 600 700 dE/dx December - dE/dx July (normalized) Vs. phi

return to talk Markus Cristinziani BaBar Drift Chamber performance – Extra material 27 / 28

Performance Background Upgrade HiLumi Extra

Fit vs. Lumi after single beam subtraction

Luminosity (1e33) 2000 4000 6000 Occupancy - Single Beam contribution (%)

• 1

1 2 3 4 5 6

Entries 2089 Mean x 3359 Mean y 1.534 RMS x 1138 RMS y 0.6452 2089

1 10

Entries 2089 Mean x 3359 Mean y 1.534 RMS x 1138 RMS y 0.6452 2089

Lumi HER 2/3, LER scan Luminosity (1e33) 2000 4000 6000 Occupancy - Single Beam contribution (%)

• 1

1 2 3 4 5 6

Entries 2120 Mean x 4161 Mean y 1.473 RMS x 1507 RMS y 0.8478 2120

1 10

Entries 2120 Mean x 4161 Mean y 1.473 RMS x 1507 RMS y 0.8478 2120

Lumi HER max, LER scan Luminosity (1e33) 2000 4000 6000 Occupancy - Single Beam contribution (%)

• 1

1 2 3 4 5 6

Entries 2825 Mean x 2537 Mean y 1.095 RMS x 1443 RMS y 0.4664 2825

1 10

Entries 2825 Mean x 2537 Mean y 1.095 RMS x 1443 RMS y 0.4664 2825

Lumi LER 2/3, HER scan

Luminosity (1e33) 2000 4000 6000 Occupancy - Single Beam contribution (%)

• 1

1 2 3 4 5 6

Entries 2516 Mean x 4006 Mean y 2.181 RMS x 1886 RMS y 0.9269 2516

1 10

Entries 2516 Mean x 4006 Mean y 2.181 RMS x 1886 RMS y 0.9269 2516

Lumi LER max, HER scan Luminosity (1e33) 2000 4000 6000 Occupancy - Single Beam contribution (%)

• 1

1 2 3 4 5 6

Entries 1865 Mean x 3523 Mean y 2.092 RMS x 1905 RMS y 0.9662 1 1864

1 10

Entries 1865 Mean x 3523 Mean y 2.092 RMS x 1905 RMS y 0.9662 1 1864

Lumi trickle, HER scan Luminosity (1e33) 2000 4000 6000 Occupancy - Single Beam contribution (%)

• 1

1 2 3 4 5 6

Entries 8671 Mean x 3259 Mean y 1.404 RMS x 1602 RMS y 0.7 8671

1 10

Entries 8671 Mean x 3259 Mean y 1.404 RMS x 1602 RMS y 0.7 8671

All good Lumi points

Markus Cristinziani BaBar Drift Chamber performance – Extra material 28 / 28