ZHanalysis


High luminosity study on 14TeV MC data to evaluate future performance of measuring ZH-->l+l- b b with 300 fb-1 and 3000 fb-1. This is a generator level simulation with parameterised smearing to mimic the detector response. A pileup of 150 is assumed.

1.People

Flavia Dias flavia.dias@cernNOSPAMPLEASE.ch

Paul Glaysher paul.glaysher@cernNOSPAMPLEASE.ch

Victoria Martin victoria.martin@edNOSPAMPLEASE.ac.uk

Wai Thong (Kevin) wthong@cernNOSPAMPLEASE.ch

2. Datasets

14TeV

List of 14TeV MC Signal and Background Samples and their full data-set name: samples14TeV.pdf

Cross Sections, Filter Efficiencies, Effective Cross Sections, Number of generated events for 14TeV samples: sampleStats.pdf

New 14TeV samples are going to be requested for some of the background samples, to match requirements of the analysis. Specifically, Sherpa Z+jets samples which are flavour orthogonal (Z+b, Z+c and Z+l) and separated in bins of Z pT. The high Z pT bin is very sensitive due to the smaller background, and the boosted topology is expected to play a more important role in the ZH analysis at 14TeV than in 7/8TeV.

8TeV

The 8TeV MC samples and their cross sections are listed in here. The cross sections include the k-factor for those samples when it is available, and is taken from the HSG5 group.

3. Smearing

The smearing parameterisation can be found here: https://svnweb.cern.ch/cern/wsvn/atlasgroups/PhysicsAnalysis/EuropeanStrategy/TruthToRecoFunctions/?#a77b691368a136c71f1fe210df6e70e07

New smearing functions are being developed by the upgrade group.

4. Overlap Removal Prescription

The overlap removal prescription is necessary for the current 14TeV samples with AlpGen. New samples using Sherpa are being requested, and are orthogonal in flavour.

5. Cutflow

For 8TeV samples, a cross check analysis was performed using the same cuts from two public results from HSG5:

HCP analysis: ATLAS-CONF-2012-161

EPS analysis: ATLAS-COM-CONF-2013-080

The 8TeV cross check aimed to be used as a sanity check of the analysis code, and to assess the smearing performance and limitations by comparing the analysis using the full simulation variables and the smeared truth variables.

For 14TeV samples, the cuts used the values from EPS analysis as a baseline, and were adapted for the high pile-up environment and optimised to give best signal over square-root of signal plus background ratio.

Besides the smeared truth variables, a cross check is ongoing, using the event by event weight to smear and rescale the full simulation 8TeV variables to 14TeV and 140 pile-up scenario, as described in Michael's slide.

6. Links to presentations:

17 July, HSG5 meeting

20 June, Upgrade meeting

22 April, HSG5 meeting

Topic attachments
I Attachment History Action Size Date Who Comment
PDFpdf 22AprilH-bbmeetoing.pdf r1 manage 1888.2 K 2013-06-11 - 11:35 PaulGlaysher  
PDFpdf 8TeV_Samples_xsections.pdf r1 manage 267.8 K 2013-07-23 - 18:31 FlaviaDias 8 TeV Samples Cross-Sections
PDFpdf ATLAS-CONF-2012-161.pdf r1 manage 3249.2 K 2013-06-10 - 12:12 PaulGlaysher CONF NOTE
PDFpdf ZHpres17July.pdf r1 manage 35371.4 K 2013-07-23 - 18:11 FlaviaDias  
PDFpdf ZHpres20June.pdf r1 manage 23578.9 K 2013-07-23 - 18:11 FlaviaDias  
PDFpdf sampleStats.pdf r1 manage 40.3 K 2013-06-10 - 12:38 PaulGlaysher  
PDFpdf samples14TeV.pdf r1 manage 24.0 K 2013-06-10 - 12:23 PaulGlaysher  
PDFpdf samples8TeV.pdf r1 manage 21.5 K 2013-06-11 - 21:09 PaulGlaysher  
Edit | Attach | Watch | Print version | History: r9 < r8 < r7 < r6 < r5 | Backlinks | Raw View | WYSIWYG | More topic actions
Topic revision: r9 - 2013-07-23 - FlaviaDias
 
    • Cern Search Icon Cern Search
    • TWiki Search Icon TWiki Search
    • Google Search Icon Google Search

    Main All webs login

This site is powered by the TWiki collaboration platform Powered by PerlCopyright & 2008-2019 by the contributing authors. All material on this collaboration platform is the property of the contributing authors.
Ideas, requests, problems regarding TWiki? Send feedback