Presentation is loading. Please wait.

Presentation is loading. Please wait.

David Berge – CAT Physics Meeting – 9 May 2008 1 Summary Hadronic Calibration Workshop 3 day workshop 14 to 16 March 2008 in Tucson, Arizona

Published byCaitlin Allen Modified over 8 years ago

Similar presentations

Presentation on theme: "David Berge – CAT Physics Meeting – 9 May 2008 1 Summary Hadronic Calibration Workshop 3 day workshop 14 to 16 March 2008 in Tucson, Arizona"— Presentation transcript:

1 David Berge – CAT Physics Meeting – 9 May 2008 1 Summary Hadronic Calibration Workshop 3 day workshop 14 to 16 March 2008 in Tucson, Arizona http://indico.cern.ch/conferenceDisplay.py?confId=26943 Session topics: 1)Monte Carlo / testbeam validation 2)Local hadronic calibration 3)Jet energy scale 4)Missing E T Selected highlights follow

2 David Berge – CAT Physics Meeting – 9 May 2008 2 Monte Carlo / Testbeam Validation Summary and numbers: –Geant4 plus hadronic interaction model QGSP (“Quark Gluon String Punchthrough”) with Bertini nucleon-nucleon cascade validated and recommended for ATLAS NOTE: Currently available fully simulated samples have QGSP only, without Bertini –Alternative fragmentation (Fritjof) does describe certain aspects of the data well, could be used for studying systematics in case parts of the full simulation samples are available with both QGSP and Fritjof (space is limited)!

3 David Berge – CAT Physics Meeting – 9 May 2008 3 Monte Carlo / Testbeam Validation Summary and numbers: –Tile numbers: Pion response (1-2%) and resolution (5%) well described Longitudinal/lateral pion shower shapes within 10% Proton longitudinal shower shape problematic: 20-40% too short

4 David Berge – CAT Physics Meeting – 9 May 2008 4 Monte Carlo / Testbeam Validation Summary and numbers: –Hadronic Endcap (HEC): Response and resolution described by QGSP, but showers too short If Bertini switched on, longitudinal shower development ok Response is ok after Birks law and time convolution –Combined testbeam: Response within 2%, resolution in MC too good

5 David Berge – CAT Physics Meeting – 9 May 2008 5 Jets Very instructive invited talk: “Theoretical aspects of jet finding” (Gavin Salam)Theoretical aspects of jet finding See also: –hep-ph/0704.0292 –hep-ph/0707.1378 –hep-ph/0802.1188

6 David Berge – CAT Physics Meeting – 9 May 2008 6 Jets

7 David Berge – CAT Physics Meeting – 9 May 2008 7 Jets

8 David Berge – CAT Physics Meeting – 9 May 2008 8 Jets So he claims ATLAS cone is not very meaningful for many processes Not sure what our comment would be

9 David Berge – CAT Physics Meeting – 9 May 2008 9 Jets

10 David Berge – CAT Physics Meeting – 9 May 2008 10 Jets Again I’m not really sure how to interpret this I’d expect his definition of “failure rate” differs from what I would call a failure of a jet algorithm

11 David Berge – CAT Physics Meeting – 9 May 2008 11 Jets Introduced the concept of jet areas as another jet observable Infinitely soft ghost particles are added uniformly to the event, the number of ghosts ending up in a jet measures the area Contamination of hard jets from minimum bias interactions is found to scale with the jet area –Proposes to use the jet area for pile-up subtraction They provide C++ jet-finding library (FastJet), featuring a range of algorithms, including jet area calculationsFastJet –Library linked to ATLAS software in rel 14 for different jet algorithms Jet transverse momentum vs. area, for Pythia LHC dijet event with 22 minimum bias interactions

12 David Berge – CAT Physics Meeting – 9 May 2008 12 Jets in ATLAS Two variants: 1.Tower jets –Towers are formed based on constituents defined in x space –Noise contributions cancel out, are not suppressed (that is, towers with negative signals are joined with adjacent ones until the signal is positive) 2.Cluster jets –Topological cell clusters are formed based on calorimeter cells with noise cut 4/2/0 (seed/neighbor/perimeter) –Noise is actually suppressed, topo clusters are real energy blobs in 3D –Noise cuts depend on pile-up

13 David Berge – CAT Physics Meeting – 9 May 2008 13 Jets in ATLAS Main algorithms: 1.Seeded (1 GeV) fixed cone (usually R=0.4 or 0.7), with split-and-merge procedure after all stable cones are found (overlap fraction 50%) 2.Fast kt implementation, usually with distance parameter 0.4 or 0.6 But also configurable: –MidPoint –Optimum jet finder –SISCone in future via FastJet external library

14 David Berge – CAT Physics Meeting – 9 May 2008 14 Hadronic Calibration in ATLAS 1.Global –Reconstruct hadronic final state objects from towers or clusters at electromagnetic energy scale –Then calibrate jets to particle level in one step, based on (the H1) weights determined from simulations – these weights absorb all detector effects 2.Local –Reconstruct calorimeter clusters and calibrate them to hadronic energy scale, in separate steps for weights and detector corrections –Reconstruct hadronic final state based on the calibrated (!) calorimeter signals

15 David Berge – CAT Physics Meeting – 9 May 2008 15 Jet Reconstruction Flow

16 David Berge – CAT Physics Meeting – 9 May 2008 16 Global vs. Local Jet Calibration Kristin Lohwasser

17 David Berge – CAT Physics Meeting – 9 May 2008 17 Global vs. Local Jet Calibration Kristin Lohwasser

18 David Berge – CAT Physics Meeting – 9 May 2008 18 Global vs. Local Jet Calibration Global calibration: –Robust for different samples, though difference visible –Restores energy very well –Improved resolution Local calibration: –Can be split and validated in separate steps –Still missing jet corrections on top of calorimeter calibration Kristin Lohwasser

19 David Berge – CAT Physics Meeting – 9 May 2008 19 Global vs. Local Jet Calibration Local calibration seems to be the preferred choice, despite currently better performance In any case, we need collision data to decide on final recommendation for jet calibration Local calibration outstanding issues –Better treatment of Tile gap cells –Improve out-of-cluster corrections –Improve dead-material corrections –Use jet moments for residual corrections on jet level –Make local calibration pile-up aware

20 David Berge – CAT Physics Meeting – 9 May 2008 20 Usage of Tracks for Hadronic Reconstruction D.Miller, A.Schwartzman, Su Dong

21 David Berge – CAT Physics Meeting – 9 May 2008 21 Usage of tracks to select Jets in the Presence of Pile-Up They also plan (ambitiously) to use the JVF for a jet-energy correction to correct for pile-up contributions on a per-jet basis, and to correct missing ET… Jet multiplicity using JVF A flat hard-scatter jet multiplicity distribution is recovered cutting on the JVF Of course crucial for any analysis related to jet multiplicity D.Miller, A.Schwartzman, Su Dong

22 David Berge – CAT Physics Meeting – 9 May 2008 22 Usage of Tracks to Improve the Jet Energy Resolution Use tracking information to extract information about jet topology, fragmentation, and charged particle distribution Apply track-based energy response corrections Does not require additional jet energy scale corrections, but the track corrections are applied after full energy scale corrections and produce improved jets at the same overall energy scale A.Schwartzman Correlation of jet response with pT(trk)/pT(cal) Also presented track multiplicity, fraction of leading track pT, track maximum opening angle

23 David Berge – CAT Physics Meeting – 9 May 2008 23 Usage of Tracks to Improve the Jet Energy Resolution Use tracking information to extract information about jet topology, fragmentation, and charged particle distribution Apply track-based energy response corrections Does not require additional jet energy scale corrections, but the track corrections are applied after full energy scale corrections and produce improved jets at the same overall energy scale A.Schwartzman

24 David Berge – CAT Physics Meeting – 9 May 2008 24 Other interesting topics Missing ET validation from data Results from cosmics (M5/M6) Jet-energy scale validation from data Pile-up, pile-up, pile-up Check the agenda: http://indico.cern.ch/conferenceDisplay.py?confId=26943

25 David Berge – CAT Physics Meeting – 9 May 2008 25 Backup

26 David Berge – CAT Physics Meeting – 9 May 2008 26 SISCone Algorithm

Download ppt "David Berge – CAT Physics Meeting – 9 May 2008 1 Summary Hadronic Calibration Workshop 3 day workshop 14 to 16 March 2008 in Tucson, Arizona"

Similar presentations

Hadron production in hard scattering Event GeneratorGEANT.

Hadron production in hard scattering Event GeneratorGEANT.
Charged Particle Jet measurements with the ALICE Experiment in pp collisions at the LHC Sidharth Kumar Prasad Wayne State University, USA for the ALICE.

Charged Particle Jet measurements with the ALICE Experiment in pp collisions at the LHC Sidharth Kumar Prasad Wayne State University, USA for the ALICE.
Inclusive jet cross-sections and correlations in Au+Au and p+p collisions at sqrt(s NN ) = 200 GeV Mateusz Ploskon For the STAR Collaboration.

Inclusive jet cross-sections and correlations in Au+Au and p+p collisions at sqrt(s NN ) = 200 GeV Mateusz Ploskon For the STAR Collaboration.
INTRODUCTION TO e/ ɣ IN ATLAS In order to acquire the full physics potential of the LHC, the ATLAS electromagnetic calorimeter must be able to identify.

INTRODUCTION TO e/ ɣ IN ATLAS In order to acquire the full physics potential of the LHC, the ATLAS electromagnetic calorimeter must be able to identify.
Lily Asquith (ANL) on behalf of ATLAS Boost 2012, Valencia jet shapes 0.

Lily Asquith (ANL) on behalf of ATLAS Boost 2012, Valencia jet shapes 0.
Jet and Jet Shapes in CMS

Jet and Jet Shapes in CMS
Michel Lefebvre, 2007/03/02Optimal Jet Finder1 Optimal Jet Finder work in progress Physics and Astronomy University of Victoria British Columbia, Canada.

Michel Lefebvre, 2007/03/02Optimal Jet Finder1 Optimal Jet Finder work in progress Physics and Astronomy University of Victoria British Columbia, Canada.
2007/03/20Optimal Jet Finder1 Physics and Astronomy University of Victoria British Columbia, Canada Damir Lelas Rolf Seuster Michel Lefebvre, Rob McPherson,

2007/03/20Optimal Jet Finder1 Physics and Astronomy University of Victoria British Columbia, Canada Damir Lelas Rolf Seuster Michel Lefebvre, Rob McPherson,
1 N. Davidson E/p single hadron energy scale check with minimum bias events Jet Note 8 Meeting 15 th May 2007.

1 N. Davidson E/p single hadron energy scale check with minimum bias events Jet Note 8 Meeting 15 th May 2007.
Introduction to Hadronic Final State Reconstruction in Collider Experiments Introduction to Hadronic Final State Reconstruction in Collider Experiments.

Introduction to Hadronic Final State Reconstruction in Collider Experiments Introduction to Hadronic Final State Reconstruction in Collider Experiments.
DØ Run II jet algorithms E. Busato (LPNHE, Paris) TeV4LHC Workshop 12/1/2004 Outline:  Introduction  The Ideal Jet Algorithm  DØ Run II Cone Jet Algorithm.

DØ Run II jet algorithms E. Busato (LPNHE, Paris) TeV4LHC Workshop 12/1/2004 Outline:  Introduction  The Ideal Jet Algorithm  DØ Run II Cone Jet Algorithm.
Introduction to Hadronic Final State Reconstruction in Collider Experiments Introduction to Hadronic Final State Reconstruction in Collider Experiments.

Introduction to Hadronic Final State Reconstruction in Collider Experiments Introduction to Hadronic Final State Reconstruction in Collider Experiments.
Introduction to Hadronic Final State Reconstruction in Collider Experiments Introduction to Hadronic Final State Reconstruction in Collider Experiments.

Introduction to Hadronic Final State Reconstruction in Collider Experiments Introduction to Hadronic Final State Reconstruction in Collider Experiments.
Jet Reconstruction in ATLAS Slide 1 Peter Loch University of Arizona Tucson, Arizona 85721 Peter Loch University of Arizona Peter Loch University of Arizona.

Jet Reconstruction in ATLAS Slide 1 Peter Loch University of Arizona Tucson, Arizona Peter Loch University of Arizona Peter Loch University of Arizona.
1 Hadronic In-Situ Calibration of the ATLAS Detector N. Davidson The University of Melbourne.

1 Hadronic In-Situ Calibration of the ATLAS Detector N. Davidson The University of Melbourne.
1 N. Davidson, E. Barberio E/p single hadron energy scale check with minimum bias event Hadronic Calibration Workshop 26 th -27 th April 2007.

1 N. Davidson, E. Barberio E/p single hadron energy scale check with minimum bias event Hadronic Calibration Workshop 26 th -27 th April 2007.
Peter Loch University of Arizona Tucson, Arizona USA

Peter Loch University of Arizona Tucson, Arizona USA
Introduction to Hadronic Final State Reconstruction in Collider Experiments Introduction to Hadronic Final State Reconstruction in Collider Experiments.

Introduction to Hadronic Final State Reconstruction in Collider Experiments Introduction to Hadronic Final State Reconstruction in Collider Experiments.
Introduction to Hadronic Final State Reconstruction in Collider Experiments Introduction to Hadronic Final State Reconstruction in Collider Experiments.

Introduction to Hadronic Final State Reconstruction in Collider Experiments Introduction to Hadronic Final State Reconstruction in Collider Experiments.
Introduction to Hadronic Final State Reconstruction in Collider Experiments Introduction to Hadronic Final State Reconstruction in Collider Experiments.

Introduction to Hadronic Final State Reconstruction in Collider Experiments Introduction to Hadronic Final State Reconstruction in Collider Experiments.

Similar presentations

Ads by Google