1. Cadet Lieutenant Amanda Fort USMA Class of 2009 From Stratham, NH
THE FINAL COUNTDOWN
FDR-2 Data Analysis
Cadet Lieutenant Amanda Fort
USMA Class of 2009
From Stratham, NH

2. Large Hadron Collider
The Large Hadron Collider was built in a 27 km-long tunnel that ranges from 50 to 175 m underground.
Designed to collide two beams of protons rotating in opposite directions accelerated by strong magnetic fields
Uses cryogenic system to cool magnets to super-conducting temperatures
Collisions expected at 7 TeV per beam

3. Inner Tracker —measures momentum of each charged particle
Calorimeter —measures energy of each charged particle
Muon Spectrometer —measures momentum and energy of muons
Magnet System —bends charged particles in order to measure their momentum
A Toroidal LHC ApparatuS
One of the four experiments on the LHC, ATLAS is designed to detect particles that result from high energy proton-proton collisions

4. FDR Data
Full Dress Rehearsal is meant to simulate 1 day of data-taking
Reconstruction is the phase of data analysis concerned with re-creating the tracks we believe the particles took based on the data
Creates an ESD: Event Summary Data
Re-Reconstruction created an AOD; Analysis Object Data, which is a subset of an ESD
Data Analysis begins with examining the AOD

5. PHYSICS!
The Higgs Boson is a theoretical *so far* particle that has mass but no energy; they exist in a field throughout the universe, and other particles that interact with them gain mass and momentum
This would explain where particles get their mass, and thus answer the question of why photons are mass-less but W and Z bosons are quite massive
Because the Higgs lifetime is so short, the only way to detect it is to look for what it might have decayed into

6. PHYSICS!
As we do not know the mass of the Higgs, there are several possibilities of what it could decay into:
Higgs mass
Channel
Below 150 GeV
H → γγ
Above 200 GeV
H → ZZ* → 4 leptons
130 GeV
H → ττ
Between 125 and 190 GeV
H → WW
120 GeV
ttH, H → bḃ
“Golden Channel” for searching for the Standard Model Higgs, because ATLAS is optimized to detect leptons and this offers the surest way to reconstruct the mass peak of the Higgs

7. Retrieving and Viewing Data
Used ATLAS Grid to find an AOD from FDR-2 that had Zμμ events
Inserted new file into previously made job Option to view in Atlantis
Uses the Athena software framework
JiveXML Interface to view events

9. Converting to a DPD D1PDs, D2PDs, D3PDs Removing collections
Skimming—removing uninteresting events
Thinning—removing unused objects
Slimming—removing properties of objects

10. Athena ROOT Access
ARA is a package that allows us to load POOL containers from ROOT without running Athena
Commands are in PyROOT
Allows us to look at individual containers from the AOD and make our own plots and histograms from collections

12. Where do we go from here…
A Zμμ DPD-Maker
Uses ARA to find:
Luminosity information
Trigger efficiency
Alignment and calibration constants
B-Field Mapping

13. Questions? Acknowledgements Artemis Paris DPD Tutorial. AtlasWeb.
ATLAS Outreach website. CERN.
LHC Outreach website. CERN.
PAT Vancouver Tutorial. AtlasWeb.
Python ARA Tutorial. AtlasWeb.
Rosati, Stefano. Standard Model Higgs Boson Searches at ATLAS. Journal of Physics: Conference Series 110 (2008) IOP Publishing.