1 MDT P ERFORMANCE WITH 2012 C OLLISION D ATA C ONTENT OF THE CONF-NOTE Mauro Iodice Muon Week –...

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MDT PERFORMANCE WITH 2012

COLLISION DATACONTENT OF THE

CONF-NOTEMauro Iodice Muon Week – Muon Performance

Meeting, May 15th, 2013

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INTRODUCTION

Mauro Iodice – Muon Week – Performance Meeting, May 15th, 2013

•Writing/Finalizing THREE CONF-NOTES is one of the short term objectives of the Muon Analysis Task Force (MATF) Working group:

-- Alignment CONF-NOTE (main results presented in several talks by Pierre-Francoise)

-- MDT Calibrations CONF-NOTE (previous talk by Mike/Ed)

-- MDT Performance with collision data CONF-NOTE, mainly focusing on: Resolution Efficiencies Dependence with background hit rates

In the following: -- list of content and main results for the MDT Performance CONF-Note

Most of the material from recent analyses by Xin FangMANY THANKS !

3Mauro Iodice – Muon Week – Performance Meeting, May 15th, 2013

MDT PERFORMANCE CONF NOTE – PROPOSED LIST OF CONTENT

1. MDT tube hit rate Vs Luminosity -- Tube average hit rates per chamber Vs Luminosity-- Saturation effects at high rates ??? (see P.Fleischmann Muon Week March 26th)

2. MDT Resolution Vs Drift Radius-- Tube hit Residuals: Establish fitting procedure-- Resolution: Definition and methods-- Resolution measurement for different types of chambers-- Comparison among different methods-- Comparison of results with different track pT selection: check results with curved segments fits at low pT-- Dependence with tube hit rates

3. Efficiencies-- Definition (Hardware efficiency / segment reconstruction efficiency)-- Efficiencies Vs radius for different types of chambers -- Dependence with tube hit rate

4. Comparison with simulation (if available/feasible)

starting project on possible aging effects of MDT tubes Vs Integrated luminosity from MDT charge response (ADC) of the tubes Vs time (and Vs position, i.e. occupancy

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MDT HIT RATES (HZ/TUBE)

Compute average tube hit rate per chamber counting “out of time” hits in TDC spectra per chamber (and divide by num. tubes) Hz/tube

TDCBarrel A

TDCEndcap A

Highest rates on EIL1 chambers37.5 KHz/tube

<LUMINOSITY> ~ 3.8 1033 cm-2s-1

For <L> ~ 3.8 1033 cm-2s-1


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Average rate per tube per chamber normalized to average tube length x 3cmHz/cm2

Highest rates on EIL/S chambers~ 44 Hz/cm2

<LUMINOSITY> ~ 3.8 1033 cm-2s-1

MDT HIT RATES NORMALIZED TO UNIT AREA (HZ/cm2)


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MDT RESOLUTION VS DRIFT RADIUS

1. MDT Resolution can be obtained by straight track fitting (segment) from

“residual widths” s(r) and extrapolation errors:

2. Can also be obtained by the geometric mean of biased and unbiased hit “residual widths” ( NIM A538 (2005) 372-383 )

Residual distribution establish fitting function

Define “residual width”


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MDT RESOLUTION – FITTING OF RESIDUALS

•Non gaussian shape close to the wire

•Fit at different radii with Double Gaussian(small contribution from non-core gaussian for r>2mm)

•Residual Width = weighted average of large and narrow gaussians widths:

Resolution estimate insensitive to Systematic offset


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MDT RESOLUTION – RESULTS

Barrel A Barrel C

Endcap A Endcap C


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MDT RESOLUTION – RESULTS

Provided we accept the fitting

procedure and methods, this is now

an established results.

Many cross-checks performed (can

be reported in the CONF-NOTE)

All results are consitent

Comparison with H8 Test-Beam data – CAVEAT:• Test Beam data taken at fixed angles – better knowledge of

extrapolation error• Test-Beam results obtained with different residual fitting procedure• ATLAS Collision data include slewing corrections (not included in

TB)


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MDT RESOLUTION– DEPENDENCE ON HIT RATE

•The data-sample was analysed in separate “regions” with increasing luminosities

•Resolutions for the EIL1 chambers have been estimated (next slides)


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EIL1 RESOLUTION – RESULTS @ DIFFERENT LUMINOSITIES

REGION ARegion A

<L> ~ 5 1033 cm-2s-

1

Region B

<L> ~ 4 1033 cm-2s-

1

Region D

<L> ~ 2 1033 cm-2s-

1

Region C

<L> ~ 3 1033 cm-2s-

1

NO EVIDENCE OF RESOLUTION DEGRADATION UP TO 5 1033 cm-2s-1 (~55 Hz/cm2)Mauro Iodice – Muon Week – Performance Meeting, May 15th, 2013

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RESOLUTION DEGRADATION FOR HIGH RATES …as expected from Test-Beam under high background rates

By S.ZIMMERMANN March 2004 (GIF)


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MDT TUBE EFFICIENCY

•Definition, method, results in “low background rate”reported many times (see e.g. Xin at Muon Week March 26th )

•In the following, the dependence with background hit rate is reported

next slide

An example for Barrel A

chambers


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EIL1 EFFICIENCY – RESULTS @ DIFFERENT LUMINOSITIES

Region A

<L> ~ 5 1033 cm-2s-1

Region B

<L> ~ 4 1033 cm-2s-1

Region D

<L> ~ 2 1033 cm-2s-1

Region C

<L> ~ 3 1033 cm-2s-1

A DROP IN EFFICIENCY of about 3% is observed from 2 1033 to 5 1033

From 20 to 50 kHz/tube

EFFICIENCY DROP WITH TUBE HIT RATE

•Good agreement with extrapolated efficiency from tube hit rates and a ~750 ns dead-time after each hit

MeasuredExtrapolation with tube hit rate


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SUMMARY

•Results on MDT performance studies with 2012 data mature for a CONF-Note

•Background hit rates: need re-analyses on different runs/Lumi (easy)

•Resolution studies:-- Procedure established-- Resolution measured with two methods agree-- No degradation of resolution observed up to a tube hit rate of ~55 Hz/cm2 (as expected)

•Efficiency studies:-- Procedure established-- Drop in efficiency observed in the Endcap Inner chambers (mainly EIL1 – following the expectations)-- Map of efficiencies per chambers to be done

•Comparison with simulations:-- Not started yet. Need to check available data sample quality/feasibility/reliability

1 MDT P ERFORMANCE WITH 2012 C OLLISION D ATA C ONTENT OF THE CONF-NOTE Mauro Iodice Muon Week –...

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