Gravitons

1
Gravitons
A first look into
RS
at ATLAS

• Tracey Berry
• Royal Holloway

2
RS Gravitons Datasets

• MC Dataset
• 3400 G?gg and 10200 G?ee Events
• Generated with Mass 1000 GeV k/Mpl0.1
• Code version 11.0.42 and reconstructed with
  FullSim                                          
                                                    
                      
• Limited reconstruction information available. -
  can't trace mother/daughter - so just use the
  highest 2 Energy/Pt e/photons in the event for
  now to lookat distributions.
• More detailed investigations to follow in
  future.
•                                                   
                                                   

Thanks to Barry King at Liverpool for generating
the samples and producing ntuples.
3
ee Invariant Mass
10190
5323
Generator level invariant mass first two e/-
with opposite charge and with Egt100
GeV                                              
                                                  
                 Reconstructed masshighest
energy 2 es in the eventwhich pass the
selection criteria
No /- requirement here
4
Reconstructed e/g Selection Criteria

•                                                  
                                                    
                                                   
                                                   
  ElectronHas a TrackIsEMel0Pt gt
  5.0Etalt2.5E/Pgt0.5WeightRatiogt0.6NBel
  NPixelgt0NHitsel    NBel NPixel
  ElecNSCTHitsi-1 ElecNTRTHitsi-1gt 5   
•                                                   
                                                    
                  PhotonisEMphot0Etphotgt5.0E
  talt2.5Charge photon0

5
Reconstructed e variables
5323
6
G?ee Distributions
peaks at p implies es back-to-back
7
Charge Reconstruction
When more generator information available will
match generated and reconstructed electrons
Reconstructed masshighest energy 2 es in the
event which pass the selection criteria
94.8
5.2
8
G?ee Events
Most events have 1 or 2 good reconstructed
electrons
9
G?gg
Reconstructed masshighest Et 2 gs in the event
which pass the selection criteria
10
2 Highest Et Photon Variables
Reconstructed information
11
G?gg
12
Future Plans

• Look at new samples which have more generator
  level information available.
• Look into reconstruction efficiency
• Investigate e/g selection criteria
• Look into backgrounds