2009 W Cross Section and Algorithm Paper

Paper 2:  W Cross Section Analysis from Run 9 Data 


Title : Measurement of the W-/W+ boson production cross sections at mid-rapidity in p+p collisions at √s=500GeV at RHIC

 

PAs : Jan Balewski, Ross Corliss, Rosi Reed, Joe Seele*, Justin Stevens, Bernd Surrow, Gene Van Buren and Scott Wissink*

* Contacts

Intended Journal - PRD

 

Abstract : We present a measurement of the W-/W+ boson production cross sections at mid-rapidity, -1<y<+1, in proton-proton collisions based on 13.7 pb-1 at √s=500GeV by the STAR experiment at RHIC. W-/W+ boson events are selected through their electron/positron decay channels. The cross sections are compared with fully resummed and NLO calculations for different sets of parton distribution functions and are consistent with theory calculations.

 

Paper Outline

  1. Introduction to W physics at RHIC
    1. Gives us information on unpolarized antiquark sea (dbar/ubar)
    2. Check of theory for AL
  2. RHIC and STAR
  3. Triggering 
  4. W Reconstruction 
    1. Clustering/Tracking/Matching
    2. Lepton Isolation
    3. QCD Background Reduction
    4. Remaining Background Subtraction
      1. Estimable Physics Backgrounds
      2. Missing EEMC Background
      3. Generic QCD Background (QCD background shapes)
    5. Charge Separation
    6. Data/MC Comparison
  5. Cross Section Measurement(s)
    1. Formulae
    2. Yields
    3. Efficiencies
      1. Trigger efficiency
      2. Reconstruction Efficiency
    4. Acceptance Correction
    5. Luminosity
      1. Vernier Scan
    6. Uncertainties
    7. Results
      1. W+/W- Integrated cross sections
      2. W+/W- eta dependent cross sections
  6. N(W+)/N(W-) Ratio Measurement
    1. Physics interest
    2. Uncertainties
    3. Results
  7. Theoretical Input
    1. RHICBOS / de Florian et. al.
    2. Different pdfs
  8. Future Plans
    1. Run RHIC run!

 


 

 

Proposed Figures: (focus on the merit, all will be B/W, graphical layout needs optimization) 

 

1) Lego plots and/or google 3D sketch-up plots

2) Signed pT balance

3) Lepton isolation (2x2/cone and/or 2x2/4x4)

4) Charge separation Plot

5) Background cocktail plots (Tau->e contamination plot,  Missing EEMC plot, Systematic uncertainty plot)

6) Raw yields (W+/W-) - the Jacobian peak plots 

7) Data/MC Comparison (W+/W-)

8)  Z vs. invariant mass


9) Luminosity plot (or vernier scan fit)

 

10) Integrated Cross Section Plot W+/W-

11) W+/W- Cross Section vs pseudorapidity