MET Jets and Leptons in 2009 Collisions (with SUSY in mind)

Introduction

For the single lepton SUSY searches (RA4 like), leptons, jets and the MET are the most important physics objects. This page contains a collection of early plots for interesting variables from the 900 GeV Collision runs in December 2009 in comparison with Monte Carlo.

Runs and Event Selection

Dataset for MC:

• /MinBias/Summer09-STARTUP3X_V8D_900GeV-v1/GEN-SIM-RECO

Dataset for data:

• /MinimumBias/BeamCommissioning09-PromptReco-v2/RECO

Currently the runs

• 123596
• '92 and '93 are not in the plots but will be added soon

are included in the plots. Unless mentioned otherwise

• a L1 Trigger Bit of 40 OR 41
• AND a good primary Vertex
• AND passing of the HCAL Noise Filter
• AND at least one global or tracker muon OR 1 Jet with pT>3 GeV

are required.

Plots

MET

For this the caloMet collection are used.

* MET:

* ME_X:

* ME_Y:

Jets

For this the ak5CaloJets are used. First the EM-fraction for all leading (highest-pt) jet is shown, all subsequent plots are only for Jets passing the loose JetID selection

• Leading Jet Electromagnetic Fraction:
  

• pT distribution of jet 0:
  

• phi distribution of jet 0:
  

• Delta phi between the leading jet and the MET:
  

Muons

The first 2 plots show the d0 (corrected for beamspot) and Number of Hits distribution for the leading muon. All subsequent plots are for "thight" Muons, meaning:

• d0 < 1cm
• nhits > 11.

• Leading muon d0:
  

• Leading muon number of hits:
  

• Leading tight muon pT:
  

• Reconstructed transverse mass (mT) of leading tight muon:
  

Effect of the BX number

For the runs 596 and 615 the number of events from "wrong" bunchcrossing is order 1%. Excluding any BX except 51 and 2724 does NOT remove the high energy Jet and MET events. This rather reduces the probability for them being cosmic.

Next Steps

• Inclusion of more runs
• Look at beam halo

-- GregorKasieczka - 08-Dec-2009