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TauPublicCollisionPlotsArchive

Introduction

Archive of public collision plots approved by the tau group which have been superseded by notes/papers. Recent plots can be found here.

Identification Efficiency Uncertainties in 2011 data (12 Jun 2012)

Percentage uncertainties on the data/MC tau identification efficiency ratio measured using Z->ττ->μh and W->τν tag and probe analyses. All efficiency ratios are consistent with unity. Measurements are made for a Likelihood based ID (LLH) and an ID based on Boosted Decision Trees (BDT), for three working points with different signal efficiencies and background rejections, and for 1-prong only, 3-prong only and 1-or 3-prong (inclusive) candidates. For each entry, the lowest uncertainty from the two analyses is chosen.

Z->tautau Measurement Plots in 2011 data (12 Jun 2012)

(Plot 1:) Visible mass distribution in the Z->ττ->μh tag and probe analysis, before applying identification to the probe-tau. The W+jets and multijet backgrounds are estimated using data-driven techniques (see ATLAS-CONF-2011-152). The data was taken in early 2011 with pileup corresponding to <μ>~6.




(Plot 2:) Visible mass distribution in the Z->ττ->μh tag and probe analysis, after applying the medium BDT identification to the probe-tau. The W+jets and multijet backgrounds are estimated using data-driven techniques (see ATLAS-CONF-2011-152). The data was taken in early 2011 with pileup corresponding to <μ>~6.




(Plot 3:) Visible mass distribution in the Z->ττ->μh tag and probe analysis, before applying identification to the probe-tau. The W+jets and multijet backgrounds are estimated using data-driven techniques (see ATLAS-CONF-2011-152). The data was taken in late 2011 with pileup corresponding to <μ>~11.




(Plot 4:) Visible mass distribution in the Z->ττ->μh tag and probe analysis, after applying the medium BDT identification to the probe-tau. The W+jets and multijet backgrounds are estimated using data-driven techniques (see ATLAS-CONF-2011-152). The data was taken in late 2011 with pileup corresponding to <μ>~11.

W->taunu Measurement Plots in 2011 data (12 Jun 2012)

(Top:) Track multiplicity distribution before tau identification of the tau candidates in the tag-and-probe W->τν event selection. The track multiplicity is computed with a pT-correlated method on the tracks within a cone of radius ΔR<0.6 with respect to the visible tau direction. The fraction of real taus, leptons and QCD jets is estimated fitting distributions in data before and after identification. The templates for real taus and leptons are estimated from Monte Carlo predictions while the template for jets is built from events in a control region in data.




(Bottom:) Track multiplicity distribution after tight BDT tau identification of the tau candidates in the tag-and-probe W->τν event selection. The track multiplicity is computed with a pT-correlated method on the tracks within a cone of radius ΔR<0.6 with respect to the visible tau direction. The fraction of real taus, leptons and QCD jets is estimated fitting distributions in data before and after identification. The templates for real taus and leptons are estimated from Monte Carlo predictions while the template for jets is built from events in a control region in data.

SUPERCEDED BY ATLAS-CONF-2012-054 Tau Energy Scale Uncertainty plots for Winter 2012 (14 Mar 2012)

(Top:) Systematic uncertainty on the tau energy scale for 1-prong decays in the central region (|η| < 0.3), as a function of tau transverse momentum. The systematic uncertainty is determined in a data-driven way. The method is similar to that described in ATLAS-CONF-2010-052 for the calorimeter jet scale uncertainty. The calorimeter response is provided by in-situ E/p measurements for p < 20 GeV and test beam measurements for p >20 GeV. Other systematic uncertainties are determined using Monte Carlo methods. Each different marker represents a separate source of uncertainty while the violet band shows the combined uncertainty from all sources.




(Bottom:) Systematic uncertainty on the tau energy scale for 3-prong decays in the endcap region, as a function of tau transverse momentum. The systematic uncertainty is determined in a data-driven way. The method is similar to that described in ATLAS-CONF-2010-052 for the calorimeter jet scale uncertainty. In the endcap region the calorimeter response is provided by in-situ E/p measurements and MC based studies. Other systematic uncertainties are determined using Monte Carlo methods. Each different marker represents a separate source of uncertainty while the violet band shows the combined uncertainty from all sources.
1-prong tau energy scale uncertainty for Winter 2012 Verification plot

SUPERCEDED BY ATLAS-CONF-2011-152 Performance plots for Summer 2011 (20 July 2011)

Inverse background efficiency (in dijet data) versus signal efficiency (in W->τν and Z->ττ Monte Carlo samples) for all discriminants on 1-prong and 3-prong candidates. Definitions for efficiencies and event selections can be found in ATLAS-CONF-2011-077. performance plot for 1-prong tau performance plot for 1-prong tau

SUPERCEDED BY ATLAS-CONF-2011-152 Update plot for tau ID efficiency measurement in 2010 analysis (18 July 2011)

(Top:) Updated summary plot for Data/MC tau identification efficiency scale factor measured in ATLAS‐CONF‐2011‐093. The Z‐>ττ cross section normalization method is added.




(Bottom:) The Z‐>ττ acceptance estimated in arXiv:1108.2016v1 is compared with the Z‐>ee/μμ cross section measured in ATLAS‐CONF‐2011‐041.
Summary plot Verification plot

SUPERCEDED BY ATLAS-CONF-2011-152 Z->ττ visible mass distributions (13 July 2011)

Visible mass between the muon and hadronically decaying tau in Z->ττ->μνντhν before and after Tau-ID is applied. The distributions are taken from the tau efficiency measurement using tag & probe with Z->ττ events, which follows closely the method from the Z->ττ cross-section measurement documented in arXiv:1108.2016v1. Visible Mass distribution for Z->tautau events before tau ID Visible Mass distribution for Z->tautau events after tau ID

SUPERCEDED BY ATLAS-CONF-2011-152 Energy Scale Systematics for 2011 Calibration (13 July 2011)

Final systematic uncertainty on the tau energy scale (TES) for 1-prong decays in the central region. Each different marker represents a separate source of uncertainty as indicated in the legend. The yellow band shows the combined uncertainty from all sources. The method is similar to that described in ATLAS- CONF-2011-077. Similar results were obtained for multi-prong tau candidates and for candidates in the endcap region. Energy scale systematic uncertainties

Z->ττ candidate event display (07 October 2010)

This is a display of an event with a candidate Z->τ+τ-->μ+νντ-hν decay in the ATLAS detector where τh denotes a hadronic tau decay.
Event properties:
pT(μ) = 18 GeV
pTvish) = 26 GeV
mvis(μ , τh) = 47 GeV
mT(μ , ETmiss) = 8 GeV
ETmiss = 7 GeV
The hadronic tau candidate has three well identified tracks.
The muon and tau candidate have opposite sign reconstructed charges.
No additional object (electron, muon or jet) was reconstructed in this event.
Z->tautau candidate event display

W->τν candidate event display (20 July 2010)

A candidate for a W->τν decay, with a hadronically decaying tau, collected on 24 May 2010.
Event properties:
pT(τ) = 29 GeV
ETmiss = 39 GeV
Δφ(τ, ETmiss ) = 3.1
mT = 68 GeV

No additional object (electron, muon or jet) was found in the event.
W->taunu candidate event display

SUPERCEDED Collision results approved on 16 December 2009

All the plots and text provided in this page summarise the results obtained in the context of the analysis of 2009 collision data and approved for presentation at conferences.

We obtained more than 1500 reconstructed tau candidates with at least one track in 900 GeV minimum bias data, where we only use candidates found from a calorimeter seed (calo-based candidates) and tracks are required to have at least one Pixel or SCT hits and pT > 500 MeV. These candidates are expected to be essentially entirely composed of background, and so are useful to test the modelling of discriminating variables for backgrounds to tau production.
Shower shapes were compared to Monte Carlo simulations of non-diffractive minimum bias events. These variables are used in tau identification.

Electromagnetic shower radius
The radius of energy deposits in electromagnetic calorimeters for calo-based candidates. This variable corresponds to the lateral development of electromagnetic showers. This is the most powerful variable to separate the tau signal from the QCD jets background. emradius_900gev.12.16.2009
Shower evolution
The mean of the EM radius as a function of the incident angle of the track on the surface of the calorimeters. With increasing track incident angle, the shower spreads in the lateral direction. emradius_ontrack_900gev.12.16.2009
Centrality fraction
The ratio of the transverse energy of calo-based candidates within a cone of ΔR<0.1 to their transverse energy within a larger cone of ΔR<0.4. centrality_fraction_900gev.12.16.2009
Isolation fraction
The fraction of the transverse energy deposited in the electromagnetic calorimeter in a cone 0.1<ΔR<0.2 around the direction of the tau candidate with respect to the transverse energy in a cone of ΔR< 0.4. isolation_fraction_900gev.12.16.2009
Cluster energy
Energy of individual clusters making up tau candidates. Clusters are 3-dimensional collections of calorimeter cells around seeds well above the noise level. cluster_energy_900gev.12.16.2009


Major updates:
-- MartinFlechl - 21-Feb-2013

Responsible: MartinFlechl
Subject: public

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Topic revision: r2 - 2013-02-22 - MartinFlechl
 
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